JP3396397B2 - Device for compensating pressure fluctuation of hydraulic system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention opens the connection on the suction side to a supply device arranged in front of the pump in order to end the feeding cycle, thereby reducing the load on the pump chamber defined by the working piston. An injection engine, preferably a large diesel engine, with at least one pump that can be rapidly removed
And the like for compensating for pressure fluctuations in a hydraulic system in a fuel supply device such as. The device is constructed with a buffer housing, which is provided with at least one balancing chamber in fluid communication with the supply device. The balancing chamber is delimited by at least one balancing piston, which is slidable between two catches arranged in the cylindrical region of the shock-absorbing housing, with respect to this balancing piston, as opposed to the balancing chamber. It is possible to apply a buffering force from the side.

[0002]

BACKGROUND OF THE INVENTION In large diesel engines of known construction, the injection pump is usually equipped with a shock absorber of the type used in this field.
This reduces the high pressure extremes caused by the sudden unloading of the pump chamber. In the currently commonly used devices, the damping force exerted on the balancing piston from the side facing away from the balancing chamber is generated only by a spring arranged behind the balancing piston. At this time, when different buffering forces are required, different springs are required. This also applies to large diesel engines. That is, a large diesel engine can be selectively driven by normal diesel oil or water-emulsified (emulsion combustion) fuel. When supplying water-emulsified fuel, an injection pump is used. It is necessary to set the pressure in the supply pump that supplies fuel to a higher level, and the buffer force will change correspondingly. To address this situation, conventionally, when switching from one fuel to the other, one or more springs that engage the balancing piston must also be replaced. This is extremely complicated and time consuming. As a result, a relatively long preparation process was required to switch from one fuel to the other.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is therefore to use simple and inexpensive means to overcome the above-mentioned drawbacks and to adapt to different pressure levels quickly and easily. The object is to improve the device of the above type.

[0004]

This object is achieved according to the invention by making it possible on the side of the balancing piston opposite the balancing chamber to supply at least a pressure-adjustable pressure medium.

In this case, it is possible to adapt the magnitude of the damping force to the individual situation by varying the pressure of the pressure medium supplied on the side of the balancing piston opposite the balancing chamber. Furthermore, if a spring which engages the balancing piston is used, the buffering force can be easily adapted by connecting or disconnecting the pressure medium.
In addition, pressure change, or connection and disconnection of pressure medium,
It can be carried out by a simple method of operating the valve. Therefore, high operability can be obtained. At the same time, the measures according to the invention open up the possibility of automating the adaptation of the shock absorber according to the invention to different pressure levels.

Advantageous configurations and advantageous embodiments of the abovementioned measures are described in the dependent claims. For large diesel engines that can supply compressed air for start-up, it is possible to supply compressed air from that same source of compressed air to the balancing piston. In this case,
By the preferred method, a pressure medium having a high pressure level is provided at substantially no cost.

In another preferred embodiment of the present invention, in a fuel injection device having a stock space in which an injection pump can be connected to the pump chamber, fuel pressurized by a supply pump is supplied to the stock space. It is possible to supply. The pressure of the buffering pressure medium supplied to the balancing piston is about 1.5 to 2.
It is set to 5 times, preferably 2 times. Empirically, this setting makes it possible to particularly effectively alleviate the generated pressure extreme value.

In another embodiment of the present invention, the balancing piston is formed in a cup shape (substantially U-shaped in section),
The outer peripheral surface and the inner peripheral surface can be sealed. In this case, the inner peripheral surface of the balancing piston is sealed to the connecting cylinder that is connected to the pressure medium source and projects into the buffer housing. This gives a favorable area ratio between the respective effective surfaces on both sides of the balancing piston. Furthermore, if it is desired to combine the spring and the pressure medium in order to generate a damping force, by means of a suitable method, at the position radially outside the connecting cylinder and behind the balancing piston, the annular A space is formed in which at least one compression spring can be arranged.

In another preferred embodiment of the invention, the cup-shaped balancing piston is surrounded by a second bush-shaped balancing piston which is sealed to the shock-absorbing housing, Sealed against the piston. The second balancing piston is moveable between two locks fixed relative to the housing, and further the second balancing piston is responsible for the cup-shaped balancing piston approaching the balancing chamber. It has a front locking portion provided so as to stop. This allows
The inner balancing piston engages with the front locking portion provided on the outer balancing piston, and the outer balancing piston itself engages with the rear locking portion on the housing side or is arranged between the locking portions. It becomes possible to realize the equilibrium state that In this case, the inner balancing piston can be retracted in case of pressure increase and can move forward with the outer balancing piston in case of pressure decrease. As a result, not only the positive pressure extreme value but also the negative pressure extreme value can be surely compensated, and cavitation is surely prevented.

[0010]

Other preferred configurations and advantageous embodiments of the above means are set forth in the remaining dependent claims, and will be apparent from the following description of the embodiments with reference to the drawings. . FIG. 1 is a schematic diagram showing a fuel supply device for a large diesel engine. FIG. 2 is a sectional view showing a fuel injection pump of the apparatus shown in FIG. Figure 3
It is a longitudinal section showing a 1st embodiment of a shock absorber by the present invention. FIG. 4 is a vertical sectional view showing a second embodiment of the shock absorber according to the present invention. FIG. 5 is a vertical sectional view showing a third embodiment of the shock absorber according to the present invention.

In FIG. 1, a large diesel engine, which can be used, for example, as a ship drive, is shown generically by a cylinder 1. Of course, in practice, many cylinders of this kind are provided. 2 for cylinder 1
One injection nozzle 2 is provided, which is connected to the injection pump 4 via a high-pressure line 3. The fuel sucked by the injection pump 4 is supplied by the supply device. The supply device extends from the tank 5 and the supply pump 6
And a supply circuit 8 having a pressure control valve 7. The supply circulation path is provided with a connection structure 9 having a supply side connection and a return side connection for the injection pump 4 and having a supply path and a return flow path, respectively. Excess fuel is recirculated from the injection nozzle 2 through the recirculation passage 10. This return path joins the return path of the connection structure 9 attached.

The injection pump 4 comprises a working piston 13 which is arranged in a cylindrical pump housing 11 and which is provided with lateral control edges 12 as is apparent from FIG. There is. The working piston defines a pump chamber 14 from which the respective high-pressure line 3 extends outward in a manner not shown here in detail. The pump housing 11 is covered with a housing cover portion 15, and the housing cover portion defines an annular stock space 16.
As shown by arrows 9a and 9b, the connection structure 9 is guided through this stock space. Therefore, in the stock space 16, fuel having the pressure given by the supply pump 6 exists. Stock space 16
It can be connected to the pump chamber 14 via the inflow opening 17 and the outflow opening 18. A valve is attached to the inflow opening 17. The outflow opening 18 is formed by the working piston 13.
It is controlled by the control edge portion 12 of.

If the valve attached to the inflow opening 17 is opened when the working piston 13 carries out the suction process, the pressure in the stock space 16 may drop sharply. Also, if the control edge 12 passes through the outflow opening 18 and thereby the load in the pump chamber 14 is suddenly removed, a sudden pressure increase may occur in the stock space 16. . In order to compensate for the above-mentioned pressure fluctuations, in particular the injection pump 4 in order to reduce the pressure maximum in the stock space 16 resulting from the sudden unloading of the pump chamber 14 and thus the pressure maximum for the entire fuel supply system. A shock absorber 19 is attached to this. The shock absorber comprises a shock-absorbing housing 20 which is flanged to the housing cover part 15, in which the equilibrium chamber 21 in fluid communication with the stock space 16 is formed. The opposite side of the equilibration chamber 21 from the stock space 16 is shown in FIGS.
It is partitioned by a balancing piston device movable between two locking portions, which will be described later with reference to FIG. Pressure can be supplied to the surface of the balancing piston device opposite the balancing chamber 21 by means of a pressure medium, for example compressed air. The supply of the pressure medium is carried out in the area behind the buffer housing 20 via a pressure medium supply line 22 which is connected to the buffer housing. When using compressed air, it is possible to supply compressed air to the pressure medium supply line 22 from a compressed air source normally used for starting a diesel engine. In this case, the pressure of the pressure medium is adapted to the pressure of the feed pump 6. At this time, the pressure of the pressure medium is 1.2 to 5 times the pressure of the supply pump 6,
It is preferable to set it to double.

In the embodiment of the damping device 19 shown in FIG. 3, the balancing piston device described above is constructed with a balancing piston 23 having a cup shape. The equilibrium piston 23 is in contact with the cylindrical region of the buffer housing 20 on the outer peripheral surface thereof, and is in contact with the connecting tubular body 24 fitted into the buffer housing 20 from the rear on the inner peripheral surface thereof. The connecting cylinder 24 has a flange 2 at a rear end portion of the buffer housing 20 which is separated from the balance chamber 21.
5 are provided. In this case, the buffer housing 20 defines an outer side, the connecting cylinder 24 defines an inner side, the rear end surface side of the balancing piston 23 defines a front side, and the flange 25 defines a rear side. The annular space 26 can be supplied with air and exhausted by a ventilation opening penetrating the flange 25.

The connecting cylinder 24 has a pressure medium supply line 22.
It is connected to the. Compressed air can be supplied to the pressure medium supply pipe line 22 by the compressor 28 in this embodiment. An air filter 29 is provided in front of the compressor 28.
And a pressure regulating valve 30 is arranged in the rear stage, and the compressed air passes through the connecting cylinder 24 to the internal space of the balance piston 23 forming the back pressure chamber 31 facing the balance chamber 21. Supplied. Therefore, the pressure in the balance chamber 21, that is, the fuel pressure generated by the supply pump 6 and the air pressure generated by the compressor 28 act on the balance piston 23. In this case, the effective forces K1 or K acting in opposite directions
2 is given by the product of the respective acting pressure and the effective area of the outer end surface A1 defining the balancing chamber 21 in the balancing piston 23 or the effective area of the inner end surface A2 defining the back pressure chamber 31.

The balance piston 23 is movable between the rear locking portion and the front locking portion shown in FIG. The rear locking portion 32 is formed by a centering collar fitted in the buffer housing 20 at the flange 25. Further, in order to form the front locking portion 33, a step portion is formed in the shock absorbing housing 20, and a collar formed so as to circulate in the balance piston 23 is engaged with the step portion.

The shock absorber normally functions as a unidirectional shock absorber that compensates for either the maximum value of the pressure or the minimum value of the pressure. In response, the back pressure chamber 31
The supply pressure to the can be set to a higher pressure or a lower pressure, and the piston 23 is engaged with either the front locking portion or the rear locking portion at a normal fuel pressure. When the back pressure chamber 31 has a higher pressure, the piston 23 engages with the front locking portion, and when the back pressure chamber has a lower pressure, the piston 23 engages with the rear locking portion. Are combined. In any case, the pressure of the compressor 28 which supplies the pressure to the back pressure chamber 31 is adjusted by the adjusting valve 30. In this regard, the equilibrium piston 23 is moved when there is a pressure change of about 0.5 bar or more, preferably 2 to 3 bar or more, when the pressure changes on the fuel side, that is, in the equilibration chamber 21. Adjustment by the adjusting valve is carried out.

The large diesel engine is, as already explained, selectively driven by different fuels, ie, for example, conventional diesel oil or water-emulsified fuel, in each case in the fuel supply region a regulating valve. Different pressures are adjusted by 7. When using water-emulsified fuels, much higher pressures are required than when using normal diesel oil. Therefore, depending on the type of each fuel,
The fuel pressure in the equilibration chamber 21 will be different. In each case, the pressure in the back pressure chamber 31 is adjusted appropriately by the regulating valve 30 in accordance with the respective fuel, in order to guarantee the above-mentioned balancing function of the balancing piston 23. In this case, higher pressure levels are set for water-emulsified fuels and lower pressure levels for regular diesel oils. This pressure level is
The pressure on the fuel side adjusted by the adjusting valve is preferably set to about 1.5 to 2.5 times, preferably twice. Then, based on the pressure level set in this way, depending on whether the maximum pressure value or the minimum pressure value is compensated, the piston 23
The actual pressure in the back pressure chamber 31 is further increased or reduced so that the desired pressure is in the desired forward, backward or intermediate position.

The embodiment shown in FIG. 4 is different from the above-mentioned embodiment shown in FIG. 3 in that the compression spring 3 is provided in the annular space 26.
The difference is that 4 is inserted. The compression spring exerts a force against the fuel pressure on the balancing piston 23. The compression spring 34 is sized so as to generate the reaction force to be applied to the piston 23 by itself without being assisted by the pressure applied to the back pressure chamber 31 when driven by the ordinary diesel oil. ing. In this case, the compression spring 34 is dimensioned by the piston 2
It is possible to set the 3 in its front or rear locking position. The spring constant of the compression spring 34 is such that the pressure change is 0.5 when the pressure on the fuel side changes.
It is possible to choose to move the balancing piston 23 when it is above bar, preferably above 2 to 3 bar. The compression spring 34 can also be dimensioned such that the piston 23 occupies an intermediate position between the catches, thereby compensating for both pressure maxima and pressure minima.

The transition to a water-emulsified fuel has been carried out,
When the pressure in the fuel supply system increases as a result, an appropriate pressure is supplied to the back pressure chamber 31 in response to this pressure increase, and this pressure supply is controlled by the pressure control valve 3
It is controlled by appropriately operating 0. This control is
It can be carried out quickly and easily manually or electrically. In this case, as already explained in connection with FIG. 3, depending on whether the pressure level provided for the water-emulsified fuel is to be compensated for the maximum pressure value or the minimum pressure value, respectively. The pressure can be adjusted to a higher or lower value.

In the embodiment shown in FIGS. 3 and 4, the piston 23 is set to the intermediate position by the pressure supplied into the back pressure chamber 31, and
It is also considered to have a very rapid continuous load change cycle and to oscillate bidirectionally about its intermediate position, thereby relaxing the maximum and minimum pressure values.

In the above-described two embodiments shown in FIGS. 3 and 4, the balancing piston 23 is hermetically sealed to the connecting cylinder 24. To this end, a seal 35, preferably formed by an O-ring, is provided in the front end region of the connecting cylinder 24. In addition, with respect to the cylindrical region of the buffer housing 20, the balance piston 23
Is liquid tightly sealed. For this purpose, the front end of the balancing piston 23 is provided with a seal 36, here again formed by an O-ring. An annular groove 37 is formed on the peripheral surface of the balancing piston 23 behind the seal. The annular groove 37 is formed and arranged so as to overlap the discharge opening 38 on the housing side at an arbitrary position of the balance piston 23. A suction conduit can be connected to the discharge opening 38. By using this means, the fuel that has penetrated through the seal 36 is released into the annular groove 37, and the discharge opening 3
It is guaranteed to be removed via 8. Therefore, the fuel enters the annular space 26, the outside through the annular space 26,
Alternatively, it is guaranteed that the back pressure chamber 31 cannot enter.

The embodiment shown in FIG. 5 is based on FIGS.
The configuration of the balancing piston device is basically different from that of the above-described embodiment shown in FIG. 2, but other components are the same. Therefore, the same components are given the same reference numerals. In the embodiment shown in FIG. 5, the balancing piston arrangement comprises two balancing pistons 23 and 39. Similar to the embodiment shown in FIGS. 3 and 4, the cup-shaped inner balancing piston 23 is a bush-shaped outer balancing piston 3.
Surrounded by 9. A collar 40 is formed behind the outer balance piston 39. Corresponding to the collar 40, a front locking portion 41 and a rear locking portion 42 are provided on the housing side, and the locking portion limits movement of the outer balance piston 39. In fact, the rear catch 42 formed by the flange 25 also works effectively for the inner balancing piston 23. Front locking portion 43 against the inner side of the balance piston 23 is thus formed on the stepped portion of the inner outer balance piston 39. For the stepped portion, the rear collar of the cup-shape of the balance piston 23 is engaged. The cup-shaped balancing piston 23 is
As described above, it is fitted on the connecting cylinder 24 that projects from the flange 25 and is fitted into the buffer housing 20. Through the compressor 28, to the connecting cylinder 24,
Compressed air can be supplied. The pressure level of compressed air is
Depending on whether water-emulsified fuel is used or normal fuel is used, it is adjusted to a high or low value by the adjusting valve 30. As described above, the spring 34
Is provided, adjustments are made by supplying or shutting off compressed air. In this respect, there is commonality with the above-described embodiments.

In this device, the front side of the annular space 26 is defined by the rear end faces of the two balancing pistons 23 and 39. In the annular space, here as well,
Ventilation openings 27 allow air supply and exhaust.
No spring is provided in this embodiment.
Therefore, no force acts on the rear end surface of the outer balance piston 39. On the annular front end surface of the outer balance piston 39, a force K3 derived from the fuel pressure in the balance chamber 21 acts, and the force K3 is applied to the outer balance piston 3.
9 is to be moved in the direction in which the equilibrium chamber 21 expands, that is, to the left in the illustrated example. The force K1 obtained as the product of the fuel pressure in the equilibrium chamber 21 and the area of the outer end surface A1 and the force K2 obtained as the product of the pressure in the back pressure chamber 31 and the area of the inner end surface A2 are The force difference in pressure, ie in the pressure supplied by the feed pump 6, is adjusted to move the balancing piston 23 in the direction of contraction of the balancing chamber 21, ie to the right in the example shown. On this occasion,
The two balancing pistons 23 and 39 are held in contact with each other. As long as the force K2 exceeds the sum of the force K1 and the force K3, the outer balance piston 39 moves in conjunction with the inner balance piston 23 and engages with its front locking portion 41. Such a state is shown in FIG.

As soon as the pressure wave reaches the balancing chamber 21, the two balancing pistons 23, 39 are moved to the left in the example shown. At this time, no force acts on the rear end of the outer balancing piston 39, so that the two balancing pistons 23 and 39 are in contact with each other until the collar 40 of the outer balancing piston engages with its rear catch 42. Hold the contact state. Then, only the inner working piston 23 is moved further rearward by itself. This causes the equilibration chamber 21 to move rapidly first, slowly secondly.
The stepwise expansion ensures that very strong pressure waves are captured and pressure fluctuations are compensated. Following this, when the injection stroke of the injection piston is carried out, the process described above is carried out in the opposite direction, which ensures that the negative pressure extremes are also mitigated.

Normally, the outer balancing piston 39 is in its rear locking position and only the inner balancing piston 23 is
It moves between the rear locking portion 42 formed on the housing side and the front locking portion 43 formed on the outer balance piston 39. If a stronger pressure drop is expected in the equilibration chamber 21 during the injection stroke of the injection pump, the inner equilibrium piston 23 is replaced by the outer equilibrium piston 39.
Move with. That is, the front locking portion 43 of the balancing piston 23 moves in a direction in which the distance to the rear locking portion 42 increases. As a result, even in the case of the suction stroke, the pressure drop in the equilibrium chamber 21 is compensated, and thus cavitation can be prevented from occurring.

In the illustrated embodiment, the outer balance piston 39 is provided with an annular groove 37 formed so as to circulate so as to overlap the discharge opening 38 on the housing side at an arbitrary piston position. There is. This annular groove is arranged behind a seal 44 formed by an O-ring which is in contact with the inner wall of the buffer housing 20. Further, the outer balance piston 39 is provided with a hole portion 45 extending radially from the annular groove 37. This radial hole is likewise arranged behind a seal 36 formed by an O-ring provided on the inner balancing piston 23, which constitutes a drainage structure.

The invention is not limited to the embodiments shown. That is, it is also possible to simply use hydraulic oil, for example, instead of compressed air as the pressure medium supplied to the balancing piston. Similarly, in the structure shown in FIG. 5, it is also considered to make the inner balancing piston 23 and / or the outer balancing piston 39 cooperate with a spring.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a fuel supply device for a large diesel engine.

FIG. 2 is a cross-sectional view showing a fuel injection pump of the device shown in FIG.

FIG. 3 is a vertical cross-sectional view showing a first embodiment of a shock absorber according to the present invention.

FIG. 4 is a vertical cross-sectional view showing a second embodiment of the shock absorber according to the present invention.

FIG. 5 is a vertical cross-sectional view showing a third embodiment of the shock absorber according to the present invention.

[Explanation of symbols]

4 injection pump 6 supply pumps 13 Working piston 14 pump room 16 stock spaces 18 Outflow opening 20 buffer housing 21 Equilibration chamber 23 Balance piston 24 Connection cylinder 25 flange 26 annular space 27 Ventilation opening 30 Pressure control valve 34 Compression spring 37 annular groove 38 Discharge opening 39 Balance piston 41, 42, 43 Locking part 45 Radial hole

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-47501 (JP, A) Fukukaihei 4-93759 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02M 55/00 F02M 55/02 310 F02M 55/04 F02M 59/44 F02M 37/00 F02M 37/06 F15B 1/053

Claims (15)

(57) [Claims] 1. Compensating for pressure fluctuations in a hydraulic system.
A device comprising at least one pump (4)
A supply device arranged and connected on the suction side of the pump (4),
Equipped with said pump (4) before connecting to said supply device
The feeding cycle ends by opening the suction side.
A pump chamber defined by a working piston (13)
It is constructed so that the load of (14) can be removed rapidly.
The device for compensating for pressure fluctuations is further configured with a buffer housing (20), the buffer housing (20)
At least is the supply device in fluid communication with 1
Two balancing chambers (21) are provided, the balancing chambers (21) being slidable and cup-shaped between two catches arranged in the cylindrical region of the buffer housing (20). Is defined by at least one counterbalanced piston (23) formed as described above and having a sealed outer peripheral surface, the counterbalanced piston (23) being supplied from a pressure medium source (28) from the side opposite the counterbalance chamber (21). Hydraulic system in a fuel supply device, such as an injection engine, which is preferably a large diesel engine, in which the pressure medium can be applied and the pressure of said pressure medium can be regulated by a pressure regulating valve (30). an apparatus for compensating for pressure variations in said buffer housing (20), outside the hydraulic system
Connected to the hydraulic system, formed as a component having a cylindrical region for accommodating the balancing piston (23) and connected to the pressure medium source (28) (2)
4) is fixed to the buffer housing (20) so as to project into the buffer housing (20), and the inner peripheral surface of the balancing piston (23) is connected to the connecting cylinder (24).
Apparatus for compensating for pressure fluctuations in the hydraulic system, characterized in that is further sealed against. 2. The pressure fluctuation compensating device according to claim 1, wherein compressed air can be supplied to a side of the balancing piston (23) opposite to the balancing chamber (21). 3. The pressure of the pressure medium supplied to the side of the balancing piston (23) opposite the balancing chamber (21) is variable in steps. 2. The pressure fluctuation compensator according to 2. 4. A large diesel engine supplied with compressed air for starting, wherein compressed air from the same compressed air source is supplied to the balancing piston (23). Item 1 up to item 3
The pressure fluctuation compensator according to the item. 5. In a fuel injection device, the injection pump (4) has a stock space (16) connectable to the pump chamber (14), and a supply pump (6) to the stock space.
A pressurized fuel can be supplied from the pressure pump, and the pressure of the pressure medium supplied to the balancing piston (23) is about 1.5 to 2.5 of the pressure of the supply pump (6).
The pressure fluctuation compensator according to any one of claims 1 to 4, wherein the pressure fluctuation compensator is doubled . 6. Supply to said balancing piston (23)
The pressure of the pressure medium is twice the pressure of the supply pump (6)
The pressure fluctuation compensation according to claim 5, wherein
apparatus. 7. The pressure fluctuation compensator according to claim 1, wherein the connecting cylinder (24) is provided with a flange (25) which can be fixed to an end surface of the buffer housing (20). . 8. outer end face and an inner end face positioned on opposite sides of the balance piston (23) (A1, A2) of the previous
The pressure in the equilibration chamber (21) is above 0.5 bar.
8. Pressure fluctuation compensator according to claim 7 , characterized in that the balancing piston (23) is configured to move when it changes. 9. On opposite sides of the balancing piston (23)
The outer and inner end surfaces (A1, A2) located are
The pressure in the equilibration chamber (21) changes by 2 bar or more.
The balance piston (23) is moved when
The pressure change according to claim 7, wherein
Motion compensation device. 10. The counterbalance piston (2) in the shape of a cup.
3) is surrounded by a bush-shaped second balancing piston (39) sealed to the cushion housing (20) and sealed to said second balancing piston (39), said second balancing piston (39) The balance piston (39) is movable between two locking parts (41, 42) fixed to the housing, and is seen from the both balance pistons (23, 39).
When the side of the balance chamber (21) is set to the front side, the second balance piston (39) is provided with a balance piston when the cup-shaped balance piston (23) moves forward.
The front locking part (43 ) for engaging with the connector (23) is provided, any one of claims 7 to 9 characterized in that
The pressure fluctuation compensator according to item 1 . 11. What is said balancing chamber (21) as viewed from one or two said balancing pistons (23, 39)?
Pressure fluctuation compensating device according to any one of claims 7 to 10 , characterized in that the annular space (26) formed on the opposite side can be evacuated by means of a ventilation opening (27). . 12. At least one compression spring (34) in the annular space (26) supported on one side by the flange (25) and on the other side by the at least one balancing piston (23 or 39). The pressure fluctuation compensating device according to claim 11 , wherein the pressure fluctuation compensating device is provided. 13. An equilibrium piston (23 or 39) sealed to the buffer housing (20) is provided with an orbiting annular groove (37) facing the housing,
The pressure fluctuation compensator according to any one of claims 1 to 12 , wherein the annular groove overlaps with a discharge opening (38) provided on the housing side at an arbitrary piston position. 14. The pressure fluctuation compensating device according to claim 13 , wherein the discharge opening is connectable to a suction device. 15. Bush-shaped balancing piston (39) with an annular groove (37) is provided with a hole (45) extending radially from said annular groove (37). The pressure fluctuation compensator according to claim 13 or 14 .