JPS6238020Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic clutch equipped with a modulation mechanism, and particularly to a hydraulic clutch suitable for industrial machinery such as forklifts, construction machinery, agricultural machinery, ships, etc.

A conventional example will be explained with reference to FIGS. 1 and 2. In FIG. 1, when hydraulic oil is introduced into the hydraulic chamber 52 in the cylinder 51 from the oil passage 54 in the clutch input shaft 53, the passage 56 in the hydraulic piston 55 is closed by the check ball 57 as shown by the two-dot chain line 57'. The hydraulic pressure in the hydraulic chamber 52 increases, and the piston 55 moves forward in the direction of arrow F, causing the friction plates 5 on the input side and the output side to move forward.
8 and 59 are pressed together. However, in the conventional example shown in FIG. 1, the radius L of the hydraulic chamber 52 is large and the area of action is wide, so in order to move the piston 55, a large amount of hydraulic oil must flow into the hydraulic chamber 52, and for this purpose, the above-mentioned clutch connection There is a drawback that the time lag between the start of the connection in operation, ie, the time lag between when the hydraulic oil starts to be introduced into the hydraulic chamber 52 and when the piston 55 actually starts to press the friction plates 58 and 59, becomes long. When the hydraulic pressure supply to the hydraulic chamber 52 is stopped, the check ball 57 returns to the position indicated by the solid line due to centrifugal force, the passage 56 is opened, and the hydraulic fluid in the hydraulic chamber 52 escapes to the friction plate installation chamber 60, so that the piston 55 The action of the return spring 61 causes the friction plates 58 and 59 to move backward and release the pressing force of the friction plates 58 and 59. However, during this shutoff operation, the hydraulic oil in the hydraulic chamber 52 is pressurized by centrifugal force, so the piston 55
cannot be quickly retracted, and the drag residual time, that is, the time from when the hydraulic pressure starts to be released until the pressing force of the friction plates 58, 59 is actually released, is disadvantageous.

To address this drawback, it may be possible to shorten the drag residual time by increasing the amount of oil discharged from the passage 56 or by strengthening the return spring 61, but in the case of a large clutch with high rotation specifications, the centrifugal force Since this becomes extremely large, it is impossible to widen the passage 56 or strengthen the spring 61 to the extent that it can cope with the centrifugal force, considering the hydraulic pressure at the time of connection.

In addition, in general conventional products, in order to prevent shock during connection, it is necessary to provide a modulation mechanism in the external hydraulic path and a conical spring in the piston 55, so the structure is complicated. There is.

In the conventional example shown in FIG. 2, instead of a general modulation mechanism, a structure is adopted in which the hydraulic chamber is divided into a small volume chamber 52b and a large volume chamber 52a, and both chambers 52a and 52b are connected by a slit 62. However, even with this structure, the drag remaining time when the clutch is disengaged is as long as in the conventional product shown in FIG.

This invention not only shortens the drug residual time, but also
The purpose is to shorten the time lag and reduce the shock when the clutch is connected, and to simplify the mechanism to reduce costs.The explanation is as follows with reference to the drawings.

In FIG. 3, which is a schematic cross-sectional view, 1 is a cylinder provided integrally with the shaft 2 on the outer peripheral side of the clutch input shaft 2, 3 is an annular piston that fits between the cylinder 1 and the shaft 2, and O-O is a cylinder. This is the crutch center line. The cylinder 1 extends in a cylindrical shape to the left in the drawing from the piston 3, and the extension part 5 has a center line slit 7 into which the outer peripheral protrusions of a plurality of annular friction plates 6 (drive plates) are slidably fitted. It is installed parallel to O-O,
A stopper 9 for preventing the friction plate 6 from sliding is attached to the inner surface of the tip end of the extension part 5. Adjacent each 2
An annular friction plate 10 (driven plate) is arranged between the two friction plates 6, 6, respectively.
A protrusion provided on the inner periphery of the cylindrical output shaft 11 is slidably fitted into a slit 12 parallel to the center line OO. A compression coil spring 13 is arranged between the output shaft 11 and the input shaft 2, the right end of the spring 13 in the figure is in pressure contact with the inner peripheral part of the piston 3, and the left end in the figure is an annular spring attached to the input shaft 2. It is pressed against the seat (not shown). A hydraulic chamber 15 is formed on the back side of the piston 3 (the end surface opposite to the friction plate 6). The hydraulic chamber 15 is divided into two chambers A and B as described later, and the inner periphery of the inner chamber B is the oil passage 1 provided inside the input shaft 2.
8 and an external oil line (not shown) to a hydraulic pump.

The piston 3 includes a cylindrical portion 21 that protrudes rearward (to the right in FIG. 3) from a portion near the inner periphery of the back surface.
When the clutch is closed as shown, the tip of the cylindrical portion 21 is in contact with the end wall of the cylinder 1. The input shaft 2 has a large diameter portion 2 into which the inner cylindrical surface of the cylindrical portion 21 is slidably fitted.
2, and a small volume chamber B is formed in an annular shape between the front end surface of the large diameter portion 22 and the inner peripheral portion of the back surface of the piston. The chamber A is formed between the cylindrical portion 21 and the outer peripheral cylindrical portion of the cylinder 1, and has a large volume. The cylindrical portion 21 is provided with one or more radially extending choke holes 24, and when the piston 3 is retracted as shown in the figure, the tube yokes 24 extend outward in the radial direction of the large diameter portion 22. and is closed (or nearly closed) by the large diameter portion 22.

25 is a chamber (space inside the clutch housing) in which the friction plates 6 and 10 are installed, and the piston 3 has a chamber 25.
For example, four holes 26 are provided to connect the room A and the room A. As shown in FIG. 4, which is a partial view of FIG. It is formed so that it is lined up with. Reference numerals 28 and 29 denote annular seal portions extending along the inner and outer peripheries of the hole group 26, and the seal portions 28 and 29 are formed by the front end surface of the annular portion protruding forward of the piston 3 as shown in FIG. When the clutch is connected, which will be described later, the clutch is pressed against the friction plate 6 in a liquid-tight manner to isolate the hole 26 from the chamber 25. Note that a seal portion can also be formed on the front end surface of the rib 27. Seal part 28, 2
As for 9, the material surface of the piston 3 can be used as is, or an O-ring can be provided with a special sealing material such as a rubber sheet on the surface to form the seal portions 28 and 29.

In the illustrated clutch disengaged state, the oil pressure in chambers A and B is released, and the piston 3 is pushed back by the spring 13. Also, room A is hall 2
6 and the seal portions 28, 29 and the friction plate 6. Since the chamber A is communicated with the chamber 25 through the gap 30 between the friction plate 6 and the friction plate 6, the chamber A is not filled with hydraulic oil.

When the clutch is connected, hydraulic pressure is introduced from the oil passage 18 to pressurize the chamber B. Receiving the hydraulic pressure in the chamber B, the piston 3 moves the spring 13 to the position where the seals 28 and 29 press the friction plate 6. Move forward against elasticity. As a result, the friction plates 6 and 10 begin to press against each other, and the clutch begins to connect. At this point, the hole 24 is communicating with the chamber B, and the hole 26 is closed by the seals 28 and 29.
After the connection is started (or even before that), hydraulic oil flows from chamber B to chamber A via the chain yoke 24, and at the same time,
The hydraulic oil in chamber A gradually becomes high in pressure while compressing air, and the piston 3 is pushed in the connecting direction by the oil pressure in both chambers A and B. Further, the portion of the friction plate 6 facing the hole 26 is also pushed by the oil pressure in the chamber A. Therefore, the friction plates 6, 10 are gradually pressed against each other with a stronger force, and finally the clutch is completely connected.

When the clutch is disconnected and the oil pressure in the oil passage 18 is released, the oil pressure in the chamber B is released, and at the same time, the oil pressure in the chamber A is released.
The hydraulic pressure also escapes to chamber B via the choke 24. Therefore, substantially simultaneously with the shutoff operation, the piston 3 is pushed back by the spring 13 and separates from the friction plate 6, creating a gap 30 between the seal portions 28, 29 and the friction plate 6.
Then, the hydraulic oil in the chamber A flows out from the hole 26 through the gap 30 into the space 25, and the pressure in the chamber A decreases rapidly. Therefore, piston 3 is spring 1
Due to the elasticity of step 3, it quickly retreats to the position shown in the figure.
The clutch is cut off.

In the clutch connecting operation described above, the piston 3
moves (idle running) from the illustrated retreat position to the connection start position due to the oil pressure in chamber B, but since chamber B has a small volume and is directly connected to the oil passage 18, the oil pressure in chamber B increases in a short time. Therefore, the idle running time (time lag) of the piston 3 is short as shown in the section OP in FIG. In FIG. 5, T is time and W is the disk (friction plate) pressing load.

In addition, in the half-clutch state from the start of connection to complete connection, the piston 3 is urged by the hydraulic pressure in both chambers A and B, but the volume of chamber A is large, and
Since hydraulic oil flows into chamber A through the chamber yoke 24, the oil pressure in chamber A increases gradually. Therefore, the pressing force of the piston 3 against the friction plates 6, 10 increases smoothly as shown in the section P-QR in FIG. 5, and the clutch is smoothly connected. Note that the oil pressures of both chambers A and B become the same at point R.

When the clutch is disconnected, the hydraulic oil in the chamber A is instantly discharged into the chamber 25 through the wide hole 26 and the gap 30, so the piston 3 quickly retreats and the drag remains for a long time (until the clutch is completely disconnected). time) will not become longer. In other words, the pushing force of the spring 13 against the piston 3 may be small, so a small spring 13 can be used. Furthermore, as described below, the time required for the gap 30 to occur is short. That is, in the connected state, the pressing force of the piston 3 against the friction plate 6 corresponds to the hydraulic pressure applied to the pressure receiving surface of the piston 3 (the right end surface in FIG. 3), but the area of the pressure receiving surface is smaller than that of the conventional piston. Compared to the area, it is narrower by the amount of the wide hole 26, so the hydraulic pressure applied to the piston 3 itself is small, and during the shutoff operation, the small spring 13 can quickly push the piston 3 back to the position away from the friction plate 6. can. Therefore, the time from the start of the shutoff operation until the hydraulic oil in chamber A is discharged is short, and in this respect as well, the drag residual time can be shortened.

As explained above, according to the present invention, the hydraulic piston 3 that presses the friction plate 6 on the input side and the friction plate 10 on the output side so as to press against each other is provided, and the hydraulic chamber 15 for the hydraulic piston 3 has a small volume. Divided into a first chamber B and a large-volume second chamber A, the first chamber B is directly connected to the hydraulic pressure supply oil passage 18, and the second chamber A is throttled (chiyoke 24).
A wide relief passage (hole 26) connecting the friction plate installation chamber 25 and the second chamber A is provided in the piston 3, and a seal is provided in pressure contact with the friction plate 6 to close the relief oil passage. Portions 28 and 29 are provided on the piston 3. Therefore, when the clutch is connected, the piston 3 can be quickly moved to the friction plate pressing start position by using the small volume chamber B, and the time lag can be shortened. After starting the connection, the piston 3 is moved using the chiyoke 24 and the large volume chamber A.
Since the hydraulic pressure can be increased smoothly, it is possible to prevent or reduce shock when the clutch is engaged. Furthermore, since there is no need to provide a dedicated modulation mechanism externally or to incorporate a conical plate or the like, the structure can be simplified and costs can be reduced. The hydraulic pressure rise characteristic is determined by the diameter, number, and position of the clutch yoke 24, and the capacity of the chamber A, so by changing the diameter and capacity mentioned above, the modulation characteristic (time T ₁ -
T ₂ ) can be determined.

Moreover, when the clutch is disengaged, the hydraulic oil in chamber A can be released through the wide hole 26, so the oil pressure in chamber A can be rapidly reduced without being affected by centrifugal force, and the drag remaining time can be shortened. can. Furthermore, since the influence of centrifugal force can be ignored, the clutch can be made larger and can rotate at higher speeds without any problems.

Note that when embodying the present invention, the choke 24 may be eliminated and a gap may be formed between the cylindrical portion 21 and the large-diameter portion 22 to function as a diaphragm. It is also possible to connect the chamber A to the oil passage 18 without using the chamber B. That is, a branch oil passage may be provided in the oil passage 18, and the branch oil passage may be connected to the chamber A via a throttle.

[Brief explanation of the drawing]

1 and 2 are schematic sectional views of a conventional hydraulic clutch, FIG. 3 is a schematic sectional view of a hydraulic clutch according to the present invention, FIG. 4 is a partial view of FIG.
The figure is a graph showing the disk pressing load characteristics of the hydraulic clutch according to the present invention. 3...Hydraulic piston, 6...Input side friction plate, 1
0... Output side friction plate, 15... Hydraulic chamber, 18...
Hydraulic supply oil path, 24... Chyoke (throttle), 25
...Friction plate installation room, 26...Hall (passage), A
...2nd room, B...1st room.

Claims (1)

[Scope of utility model registration request] A hydraulic piston is provided to press the input-side friction plate and the output-side friction plate into pressure contact with each other, and the hydraulic chambers for the hydraulic piston are divided into a first chamber with a small volume and a second chamber with a large volume.
The first chamber is directly connected to the hydraulic supply oil path,
The second chamber is connected to the hydraulic pressure supply oil path via a throttle, a wide relief passage connecting the friction plate installation chamber and the second chamber is provided on the piston, and a seal portion is provided on the piston that presses against the friction plate and closes the relief passage. A hydraulic clutch characterized by: