JPS6357647B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a device for preventing jamming of a hydraulic clutch which performs forward/reverse switching, mainly in a marine reduction/reversing gear.

Conventional technology Marine reduction/reversing gears equipped with hydraulic clutches:
In order to prevent shock when the clutch is engaged, a shock absorber is provided in the hydraulic circuit (see, for example, Japanese Utility Model Publication No. 19475/1983 and Japanese Utility Model Publication No. 9836/1983).

FIG. 8 shows a conventional circuit equipped with such a shock absorber. The pressure oil in the tank 2 sucked up by the hydraulic oil pump 1 is switched by the switching valve 3, and then transferred to each main passage 4,
5 selectively supplies the forward and reverse clutches 6 and 7 from one side. The shock absorber 8 is disposed in the middle of the main passages 4, 5, with oil chambers 10, 11 on both sides of the piston 9 communicating with one of the main passages 4, 5, respectively.

In the above, when the switching valve 3 is switched to one of forward and backward movement, for example, to the reverse side, the hydraulic pressure of the forward clutch 6 is discharged from the main passage 4 leading to the forward clutch 6, through the switching valve 3, and from the drain passage. At this time, one oil chamber 10 of the shock absorber 8
The oil contained in the is also discharged to this main passage 4,
In conjunction with this, the piston 9 in the shock absorber 8 moves, and pressurized oil is supplied into the oil chamber 11 on the reverse clutch 7 side to prevent the reverse clutch 7 from suddenly engaging.

Problems to be Solved by the Invention Generally, the reason why such a shock absorber 8 is provided in the main passages 4, 5 of the forward/reverse clutches 6, 7 is that when switching from the neutral position to either forward or reverse, The pressure oil supplied to the clutches 6 and 7 is changed to isobaric (neutral pressure) for a certain period of time,
This is to allow the clutch to fit in after a certain amount of time. For example, if the ship is traveling forward and switches from that position to the astern side, the driven side of the astern clutch is being rotated from the propeller side in the same direction as the forward direction, and immediately remains in that state. When the clutch enters the engagement operation, the friction plates rotating in opposite directions come into contact with each other, which may cause damage to the friction plates or stalling of the engine. The shock absorber maintains neutral pressure for a certain period of time in order to prevent shock when the friction plate is inserted into contact with the friction plate in the reverse rotation state. In general, a slow-fitting valve is used to gradually bring the friction plates into contact in order to slowly perform the fitting operation after the friction plates begin to come into contact with each other.

In the shock absorber for performing such an operation, in the conventional device described above, the return oil of the shock absorber 8 joins the main passages 4 and 5 of the forward and reverse clutches 6 and 7,
Since the oil is discharged to the drain side, a large amount of returned oil must be discharged through one drain passage, which is disadvantageous in that it cannot be discharged smoothly. Therefore, for example, if you perform a so-called "clutch turn" in which you switch from the forward position to the reverse position all at once, the return oil on the actuated side (forward side) in the shock absorber 8 will not be drained smoothly. There is a disadvantage that the pressurized oil on the operating side (reverse side) immediately enters the insertion operation without being able to change the neutral pressure isobarically for a certain period of time as described above, and the insertion shock becomes large. Of course, as mentioned above, a slow-fitting valve is provided to gently perform the operation after fitting, but even so, during such a crush turn, such a slow-fitting valve alone cannot absorb the shock. It is.

In this case, a shock absorber that absorbs the shock when the forward clutch 6 is engaged and a shock absorber that absorbs the shock of the reverse clutch 7 are provided separately, that is, both clutches 6,
If separate pistons were used as the shock absorbers for preventing shock in No. 7, this problem would be solved, but if this was done, at least two
This requires separate pistons, which increases the size of the device and increases costs. Therefore, it is desirable to use a common piston for the forward and reverse sides as much as possible.

This invention uses a common piston for the shock absorber mechanisms on the forward and reverse sides, and allows the shock absorber to quickly return to neutral as described above. The purpose of this invention is to provide a device that does not cause a large jamming shock even when such a sudden switching operation is performed.

Means for Solving the Problems In order to solve these problems, the present invention provides a hydraulic circuit that selectively supplies pressure oil from a hydraulic oil pump to one of the forward and reverse clutches via a switching valve. , a shock absorber equipped with one hydraulic piston operated by the hydraulic pressure of each main passage to the forward and reverse clutches is provided in communication with each of the main passages, and a drain passage is provided for returning the pressure oil of the shock absorber. is provided independently from the main passage, and an opening/closing mechanism for opening the drain passage when in neutral is directly connected to the switching valve so that it operates directly in response to the switching operation of the switching valve without using hydraulic pressure. It is characterized by being

In this invention, as a means for directly operating the opening/closing mechanism for opening the drain passage of the shock absorber in neutral state without using hydraulic pressure, for example, as shown in this embodiment, the switching of the drain passage is performed on the spool of the switching valve. Therefore, it is possible to do it directly.

Operation When the switching valve 24 is switched to forward or reverse, the return oil from the non-operating clutch 27 or 28 passes through the switching valve 24 from the main passage 25 or 26 and returns to the tank 22 side from the drain passage 39, but the oil returns to the tank 22 side from the drain passage 39. The return oil of the absorber 33 flows through the main passages 25, 2.
A drain passage 37 separate from the return oil on the 6 side,
62 and returned to the tank 22 side.

Embodiments Hereinafter, the structure of the present invention will be explained based on illustrated embodiments. In FIG. 1, 21 is a hydraulic oil pump, and the pressure oil in the tank 22 sucked up by the hydraulic oil pump 21 is , is sent from the primary main passage 23 to the switching valve 24, and this switching valve 24
After the direction has been changed by the forward or reverse main passages 25, 26, it is selectively supplied to either the forward clutch 27 or the reverse clutch 28. Reference numeral 29 indicates a safety valve provided in the middle of the primary main passage 23. Also, a branch passage 30 branching from the primary main passage 23 has a front and
When the reverse clutches 27 and 28 are engaged, the clutch 2
A loose fitting valve 31 with a pressure regulating valve is provided for adjusting the pressure supplied to the clutches 7, 28 and gently fitting the clutches 27, 28. Reference numeral 32 denotes a regulating pressure passage for operating the loose fitting valve 31, and this regulating pressure passage 32 communicates with one of the main passages 25 and 26 only when switching to the forward or reverse position. There is. Further, a shock absorber 33 is disposed in the middle of the regulating pressure passage 32 in parallel with the loose fitting valve 31. 3
4 is a variable throttle provided in the middle of the adjustment pressure passage 32 before the shock absorber 33. Further, 35 indicates an inlet port to the oil chamber of the shock absorber 33, and in addition to this inlet port 35, the shock absorber 33 has an outlet port 36, and this outlet port 36 is connected to the loose fitting valve 31. It joins a drain passage 37 and returns to the tank independently of the return oil from the forward and reverse clutches 27, 28. 38 is a one-way valve disposed in the middle of the drain passage 37 of the loose fitting valve 31, and is designed to open only in the drain direction. Although not shown for the sake of simplicity, the drain passage 37 of the loose fitting valve 31 is connected to the tank through the switching valve 24.
The passage is opened only when the switching valve 24 is in the neutral position. That is, in this embodiment, the drain passage 37 is directly opened by the switching valve 24 when the switching valve 24 is switched to the neutral position.

To explain the flow of pressure oil based on the above structure,
For example, when the switching valve 24 is switched to the forward side, pressure oil from the hydraulic oil pump 21 is supplied to the forward clutch 27 from the primary main passage 23 through the forward main passage 25, and is supplied to the reverse clutch 28 side. The main passage 26 leads to a clutch drain passage 39. At this time, the adjustment pressure passage 32
is the forward main passage 25 in the switching valve 24.
It communicates only on the side. That is, the pressure oil in the forward main passage 25 is supplied from the adjustment pressure passage 32 to the shock absorber 33 and the loose fitting valve 31. When the switching valve 24 is switched from the forward position to the reverse position in order to perform a crush turn from such a state, the drain passage of the loose-fit valve 31 is 37 communicates with the tank side, the pressure oil in the loose fitting valve 31 is discharged, and along with this, the pressure oil in the shock absorber 33 also joins this drain passage 37 and is discharged. In addition, the return spring 40 of the loose fitting valve 31
is stronger than the return spring 41 of the shock absorber 33. On the other hand, since the forward main passage 25 also leads to the drain passage 39 side, the water is discharged from the clutch drain passage 39 to the tank side.

When the switching valve 24 moves to the reverse position, the adjustment pressure passage 32 communicates with the reverse main passage 26, so that the pressure oil supplied to the reverse main passage 26 is transferred from the adjustment pressure passage 32 to the loose fitting valve 31. and is supplied to the shock absorber 33, and the reverse clutch 2
Adjust the hydraulic pressure supplied to 8 and loosen the shock when fitting.

In this embodiment, the shock absorber 3
3, it is only necessary to adjust the supply pressure to the loose fitting valve 31, and therefore it is possible to directly connect the main passage 2 as in the conventional case.
Compared to the case where the pressure of 5 or 26 is adjusted, there is an advantage that a small device with a small capacity is sufficient.

FIGS. 2 and 3 show specific examples of such a shock absorber 33. A piston 52 is slidably inserted into the case 51, and one hydraulic chamber 5 is partitioned by the piston 52.
3, an inlet port 35 is formed, while an outlet port 36 is formed diametrically opposite the inlet port 35. 58 is a lid that closes the opening of the case 51 on the side opposite to the hydraulic chamber 53, and the stroke adjustment bolt 54 is screwed through the lid 58. A cylindrical piston receiving member 55 is integrally formed within the case 51 at the inner end of the stroke adjustment bolt 54, and a spring receiver 56 is slidably inserted into the piston receiving member 55. With,
The return spring 41 is interposed between the spring receiver 56 and the piston 52. Another spring pressure adjustment bolt 57 is screwed through the stroke adjustment bolt 54 in its longitudinal direction, and its inner end is in contact with the back surface of the spring receiver 56 . Pressure oil entering the hydraulic chamber 53 from the inlet port 35 pushes back the piston 52 against the pressure of the return spring 41, but the piston 52 is stopped at the position where it contacts the tip of the piston receiving member 55. It's getting old. Therefore, by adjusting the screwing amount of the stroke adjusting bolt 54, the stroke of the piston 52 can be adjusted, and on the other hand, by adjusting the screwing amount of the spring pressure adjusting bolt 57, the spring receiver can be adjusted. Change the position of 56 and return spring 4.
1 pressure can be adjusted. That is, even if the neutral pressure is changed in order to change the engagement time, by adjusting the stroke and spring pressure of this piston 52, the optimum engagement point can be selected accordingly, and the clutch engagement time can be adjusted. It is possible to prevent the shock noise.

FIG. 4 shows another embodiment of the invention.
In this embodiment, the shock absorber 33 and the loose fitting valve 31 are connected in series, and the relief port 61 provided in the shock absorber 33 is connected to the loose fitting valve 31.
The oil leaking from the shock absorber 33 is supplied to the loose fitting valve 31 by communicating with the side. Further, the drain passage 62 of the shock absorber 33 is provided separately from the drain passage 37 of the loose fitting valve 31, so that the return oil of the loose fitting valve 31 can also be discharged independently.

FIG. 5 shows the specific structure of the shock absorber 33 and the loose fitting valve 31. The shock absorber 33 includes a slidable piston 72 inside a case 71, and both sides of the piston 72 are hydraulic chambers 73, 74, and return springs 75, 76 are interposed in these hydraulic chambers 73, 74.
This causes the piston 72 to return to the neutral position. The case 71 also has a pair of inlet ports 77, 7 communicating with the respective hydraulic chambers 73, 74.
8, and these inlet ports 77 and 78 selectively communicate with one of the forward main passage 25 and the reverse main passage 26 of the switching valve 24 and the drain passage 62. On the other hand, a relief hole 61 formed in the center of the case 71 communicates with an inlet port 79 of the loose fitting valve 31.

FIG. 5 shows a state in which the shock absorber 33 is switched to the forward position.
One inlet port 78 of the forward main passage 25
The pressure oil in the main passage 25 is supplied from the inlet port 78 to one hydraulic chamber 74,
The piston 72 is moved to the left in the figure. On the other hand, another inlet port 77 communicates with a drain port 80 of the switching valve 24 . Further, in this state, the relief hole 61 is in an open state, and the pressure oil that has entered the hydraulic chamber 74 is also supplied to the loose fitting valve 31 side.

When the switching valve 24 is switched to the reverse direction from the state shown in FIG.
In the neutral position shown, the shock absorber 33
Both the inlet ports 77 and 78 communicate with the drain ports 80 and 80 of the switching valve 24, so the water is passed through the drain passage 62 from the drain ports 80 and 80, independent of the pressure oil in the main passage 25 on the forward side. The piston 72 returns to the center position.
At this time, the relief hole 6 of the shock absorber 33
1 is blocked, the pressure oil to the loose fitting valve 31 side is cut off, and the drain passage 37 of the loose fitting valve 31 is opened in the switching valve 24, so that the pressure oil is absorbed by the pressure of the return spring 40. Therefore, it is discharged from the drain passage 37.

Then, when the switching valve 24 is switched to the reverse position shown in FIG. Pressurized oil enters and pushes the piston 72 back to the opposite side from the forward position, thereby causing the reverse clutch 28
The pressure oil supplied to the side is maintained at an equal pressure for a certain period of time as described above, and then the oil pressure is gradually increased by the operation of the slow-fitting valve 31 to soften the shock at the time of fitting. Also in this embodiment, the shock absorber 33 may have a small capacity that is sufficient to operate the loose fitting valve 31, which has the advantage of being miniaturized.

Effects of the Invention As described above, according to the present invention, since the drain passage of the shock absorber is provided independently from the drain passages of the forward and reverse clutches, the return oil of the shock absorber and the return oil of the main passage are Unlike the oil in the shock absorber that is discharged after merging the oil, the oil in the shock absorber is quickly discharged. Therefore, even when performing a clutch turn where the oil is suddenly changed from the forward position to the reverse position, the operation of the shock absorber is prevented. This is done reliably and has the effect of preventing stuck-in shock, engine stalling, and damage to the friction plates. In particular, in this invention, when returning from an operating position such as a forward position to a neutral position, the drain passage of the shock absorber is directly opened by the switching valve without using hydraulic pressure or the like, so that the opening operation of the drain passage is prevented. The effect is that the operation is carried out quickly and the shock absorber is operated more reliably. Of course, since one piston is used in common to absorb the shocks on the forward and reverse sides, the overall structure is small and can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a hydraulic circuit diagram showing a first embodiment of the present invention, FIG. 2 is a front view of its shock absorber,
FIG. 3 is a longitudinal sectional view, and FIG. 4 is a second cross-sectional view of the present invention.
Hydraulic circuit diagrams, FIGS. 5 to 7, show examples of
FIG. 5 is a vertical sectional view showing the specific operating state of the shock absorber and the loose-fitting valve, in which FIG. 5 shows the forward position, FIG. 6 shows the neutral position, FIG. 7 shows the reverse position, and FIG. 8 shows the conventional example. It is a hydraulic circuit diagram showing. 21...Hydraulic oil pump, 24...Switching valve, 27
...Forward clutch, 28...Reverse clutch, 31
...Loose fitting valve, 33...Shock absorber, 3
7, 62, 39...Drain passage.

Claims (1)

[Scope of Claims] 1. In a hydraulic circuit that selectively supplies pressure oil from a hydraulic oil pump to one of the forward and reverse clutches via a switching valve, the oil pressure in each main passage to the front and reverse clutches A shock absorber equipped with one operating hydraulic piston is provided in communication with each of the above main passages, and a drain passage for returning the pressure oil of the shock absorber is provided independently from the main passage. An intrusion shock prevention device for a hydraulic clutch, characterized in that an opening/closing mechanism for opening a drain passage is directly connected to the switching valve so as to be operated directly according to the switching operation of the switching valve without using hydraulic pressure. . 2. The scope of the patent claims that a slow-fitting valve that adjusts the hydraulic pressure to each forward and reverse clutch is arranged in parallel with a shock absorber, and the return oil of the shock absorber and the slow-fitting valve is combined and discharged from a drain passage. The device for preventing jamming of a hydraulic clutch according to item 1. 3. A shock absorber is placed in series with the loose-fitting valve in the middle of the path to the loose-fitting valve that adjusts the oil pressure to each forward and reverse clutch, and the return oil from the shock absorber and the loose-fitting valve is drained into separate drains. An intrusion shock prevention device for a hydraulic clutch according to claim 1, wherein the hydraulic clutch is discharged from a passage.