Clutch device

Abstract

To appropriately control the flow rate of oil in the oil passage when the clutch pedal is released. [Solution] A flow rate variable mechanism 30 is installed in the large-diameter portion 252 of the oil passage 25. The flow rate variable mechanism 30 includes a support member 32 installed in an immovable state in the large-diameter portion 252, an orifice member 36 positioned inside the cylindrical portion 34 of the support member 32, and a spring 40 that biases the orifice member 36 in the forward direction X1. A groove 34a extending in the return direction X2 is formed on the inner circumferential surface of the cylindrical portion 34. The orifice member 36 has a projection 38 that is housed in the groove 34a. The groove 34a and the projection 38 are configured to prevent the orifice member 36 from tilting with respect to the axis 34b of the cylindrical portion 34.

Description

Technical Field

[0001] The present invention relates to a clutch device mounted on a vehicle.

Background Art

[0002] Patent Document 1 discloses an example of a clutch device that operates a clutch disposed between an engine and a transmission mechanism of a vehicle. The clutch device includes a flow rate variable device provided in an oil flow path connected to a clutch master cylinder and a clutch release cylinder. The flow path variable device is provided with a clutch return path through which oil flows from the clutch release cylinder toward the clutch master cylinder when the clutch pedal is released. A solenoid valve for varying the flow rate of oil in the clutch return path is installed in the clutch return path. Therefore, in this clutch device, the flow rate of oil in the clutch return path is adjusted by controlling the solenoid valve by a control unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above clutch device, the flow rate of oil in the clutch return path is adjusted according to an instruction from the control unit. Therefore, if the instruction from the control unit is delayed or the control unit issues an incorrect instruction, there is a possibility that the flow rate of oil in the clutch return path cannot be appropriately adjusted.

Means for Solving the Problems

[0005] A clutch device for solving the above problems interrupts power transmission via the clutch when the clutch pedal is pressed, by allowing oil to flow through the oil passage in the forward direction, which is from the clutch master cylinder to the clutch release cylinder, while allowing power transmission via the clutch when the clutch pedal is released, by allowing oil to flow through the oil passage in the return direction, which is the opposite direction to the forward direction. In this clutch device, the oil passage has a small diameter portion and a large diameter portion which is positioned in the return direction more than the small diameter portion and has a larger diameter than the small diameter portion. The large diameter portion is provided with a flow rate variable mechanism for adjusting the flow rate of oil in the oil passage. The flow rate variable mechanism is installed in an immovable state in the oil passage and comprises a support member having a disc portion and a cylindrical portion extending from the outer peripheral edge of the disc portion in the return direction, an orifice member which is displaced inside the cylindrical portion in the return direction and the forward direction, and a spring which biases the orifice member in the forward direction. A groove extending in the return direction is formed on the inner circumferential surface of the cylindrical portion. The orifice member has a ring-shaped body and a projection that protrudes radially outward from the outer circumference of the body and is housed in the groove. The groove and the projection are configured to prevent the orifice member from tilting with respect to the axis of the cylindrical portion. [Effects of the Invention]

[0006] According to the above clutch device, the flow rate of oil in the oil passage can be appropriately controlled when the clutch pedal is released. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram showing the clutch device of an embodiment. [Figure 2] Figures 2(a) and 2(b) are schematic cross-sectional views showing the variable flow rate mechanism of the clutch device in Figure 1. [Figure 3]Figure 3 is a schematic cross-sectional view showing the support member and orifice in the variable flow mechanism shown in Figure 2. [Modes for carrying out the invention]

[0008] An embodiment of a clutch device installed in a vehicle will be described below with reference to Figures 1 to 3. As shown in Figure 1, the clutch device 20 includes a clutch 21 located in the power transmission path from the engine 11 to the transmission mechanism 12. When the clutch pedal 22 is depressed, the clutch device 20 cuts off power transmission from the engine 11 to the transmission mechanism 12 via the clutch 21. On the other hand, when the clutch pedal 22 is not depressed, the clutch device 20 allows power transmission from the engine 11 to the transmission mechanism 12 via the clutch 21.

[0009] The clutch device 20 includes a clutch master cylinder 23 to which the clutch pedal 22 is connected, a clutch release cylinder 24, and an oil passage 25. The oil passage 25 is an oil passage connecting the clutch master cylinder 23 and the clutch release cylinder 24. When the clutch pedal 22 is pressed down, hydraulic pressure is generated in the clutch master cylinder 23, causing oil to flow through the oil passage 25 from the clutch master cylinder 23 to the clutch release cylinder 24. As a result, the hydraulic pressure in the clutch release cylinder 24 increases, and the clutch 21 is released by the operation of the clutch release cylinder 24. This interrupts power transmission through the clutch 21. On the other hand, when the clutch pedal 22 is released, the hydraulic pressure in the clutch master cylinder 23 decreases. As a result, oil flows through the oil passage 25 from the clutch release cylinder 24 to the clutch master cylinder 23. As a result, the hydraulic pressure in the clutch release cylinder 24 decreases, and the clutch 21 is engaged by the operation of the clutch release cylinder 24. This allows power transmission via the clutch 21.

[0010] Hereafter, the direction of oil flow in the oil passage 25 when the clutch pedal 22 is depressed will be referred to as the "forward direction X1". The direction of oil flow in the oil passage 25 when the clutch pedal 22 is released will be referred to as the "return direction X2". The return direction X2 is the opposite direction to the forward direction X1.

[0011] As shown in Figures 1 and 2, the oil passage 25 is provided with a flow rate variable mechanism 30 that adjusts the flow rate of oil in the return direction X2 when the clutch pedal 22 is released. The flow rate variable mechanism 30 operates so that the oil flow rate decreases as the operating speed when the clutch pedal 22 is released increases.

[0012] As shown in Figures 2(a) and (b), the oil passage 25 is provided with a small-diameter section 251 and a large-diameter section 252 which is located in the return direction X2 relative to the small-diameter section 251. The diameter of the large-diameter section 252 is larger than the diameter of the small-diameter section 251. A flow rate variable mechanism 30 is located in the large-diameter section 252.

[0013] The variable flow mechanism 30 comprises a cylindrical bush 31, a support member 32 and an orifice member 36 located in the forward direction X1 relative to the bush 31, and a spring 40 located between the bush 31 and the orifice member 36. The bush 31 is cylindrical and is installed in an immovable state within the oil passage 25.

[0014] The support member 32 is installed in an immovable state within the oil passage 25. Specifically, the support member 32 is positioned at the boundary between the large-diameter portion 252 and the small-diameter portion 251. The support member 32 has a disc portion 33 and a cylindrical portion 34 extending in the return direction X2 from the outer peripheral edge of the disc portion 33. A through hole 33a is provided in the center of the disc portion 33. Two grooves 34a extending in the return direction X2 are provided on the inner circumferential surface of the cylindrical portion 34.

[0015] The orifice member 36 is supported by the support member 32 so as to be movable in the forward direction X1 and the return direction X2 inside the cylindrical portion 34. The orifice member 36 has a ring-shaped body 37 and two protrusions 38 projecting radially outward from the outer circumference of the body 37. A through hole 37a is provided in the center of the body 37.

[0016] As shown in Figure 3, the projection 38 is housed in the groove 34a. Furthermore, a gap SP is interposed between the outer circumferential surface of the main body 37 and the inner circumferential surface of the cylindrical portion 34. The spring 40 biases the orifice member 36 in the forward direction X1.

[0017] When the clutch pedal 22 is depressed and oil flows through the oil passage 25 in the forward direction X1, the biasing force of the spring 40 presses the orifice member 36 against the disc portion 33 of the support member 32, as shown in Figure 2(a). At this time, the through hole 33a of the disc portion 33 and the through hole 37a of the orifice member 36 are in communication. Therefore, the oil discharged from the clutch master cylinder 23 into the oil passage 25 passes through the through holes 33a and 37a and is supplied to the clutch release cylinder 24.

[0018] On the other hand, when the clutch pedal 22 is released, oil flows through the oil passage 25 in the return direction X2. In this case, the position of the orifice member 36 changes depending on the flow rate, i.e., the flow velocity, of the oil flowing through the oil passage 25 in the return direction X2.

[0019] The hydraulic pressure in the oil passage 25 is referred to as "passage hydraulic pressure Po". The passage hydraulic pressure Po varies depending on the flow rate (i.e., flow velocity) of the oil in the oil passage 25. According to Bernoulli's theorem, the greater the flow rate, the lower the passage hydraulic pressure Po. The lower the passage hydraulic pressure Po, the smaller the load D applied to the orifice member 36 from the oil flowing in the return path direction X2. The load D acts on the orifice member 36 in the return path direction X2. And the orifice member 36 is positioned at a position where the load D and the restoring force of the spring 40 are balanced. That is, when the load D is greater than the restoring force of the spring 40, the orifice member 36 moves in the return path direction X2. In this case, as shown in Fig. 2(b), since the orifice member 36 separates from the disk portion 33, the oil passing through the through hole 33a flows through both the gap SP between the main body 37 of the orifice member 36 and the cylindrical portion 34, and the through hole 37a.

[0020] On the other hand, when the load D is smaller than the restoring force of the spring 40, the orifice member 36 moves in the forward path direction X1. And when the orifice member 36 abuts against the disk portion 33 as shown in Fig. 2(a), the flow of oil through the above-mentioned gap SP is restricted.

[0021] The operation and effects of this embodiment will be described. When the operating speed when the clutch pedal 22 is being released is relatively small, the flow rate of the oil flowing in the oil passage 25 in the return path direction X2 is also relatively small. The smaller the flow rate of the oil in this way, the higher the passage hydraulic pressure Po. At this time, if the load D is greater than the spring load of the spring 40 due to the relatively small operating speed, the orifice member 36 moves in the return path direction X2 against the force input from the spring 40. As a result, as shown in Fig. 2(b), the orifice member 36 separates from the disk portion 33 of the support member 32. Then, not only does oil flow through the through hole 37a, but oil also flows through the gap SP between the orifice member 36 and the peripheral wall of the cylindrical portion 34 of the support member 32. That is, the flow path cross-sectional area becomes larger compared to the case where the orifice member 36 is pressed against the disk portion 33. Thereby, the return speed of the clutch pedal 22 is stabilized.

[0022] On the other hand, when the operating speed when the clutch pedal 22 is depressed is relatively high, the flow rate of the oil flowing in the oil flow path 25 in the return direction X2 is also relatively high. As the flow rate of the oil increases in this way, the flow path oil pressure Po decreases. At this time, since the operating speed is relatively high, the load D becomes smaller than the spring load of the spring 40. Then, as shown in Fig. 2(a), the orifice member 36 is pressed against the disk portion 33 by the force input from the spring 40. In this case, although the oil flows through the through hole 37a, the oil does not flow through the gap SP. As a result, the hydraulic pressure in the clutch release cylinder 24 decreases relatively gently. As a result, the clutch 21 is engaged early and the vehicle starts suddenly is suppressed. Thereby, an increase in the load applied to the components of the clutch 21 and the transmission mechanism 12 can be suppressed.

[0023] Also, in the present embodiment, as shown in Fig. 3, the protrusion 38 of the orifice member 36 is housed in the groove 34a of the cylindrical portion 34. And the gap between the side wall of the groove 34a and the protrusion 38 is very narrow. Therefore, the orifice member 36 is suppressed from tilting with respect to the axis 34b of the cylindrical portion 34.

[0024] Therefore, the clutch device 20 can appropriately control the flow rate of the oil in the oil flow path 25 when the clutch pedal 22 is depressed.

Explanation of reference numerals

[0025] 20... clutch device, 21... clutch, 22... clutch pedal, 23... clutch master cylinder, 24... clutch release cylinder, 25... oil flow path, 251... small diameter portion, 252... large diameter portion, 30... flow rate variable mechanism, 32... support member, 33... disk portion, 34... cylindrical portion, 34a... groove, 34b... axis, 36... orifice member, 37... body, 38... protrusion, 40... spring.

Claims

[Claim 1] In a clutch device in which, when the clutch pedal is pressed, oil flows through the oil passage in the forward direction, from the clutch master cylinder to the clutch release cylinder, thereby interrupting power transmission via the clutch, and when the clutch pedal is released, oil flows through the oil passage in the return direction, opposite to the forward direction, thereby allowing power transmission via the clutch, The oil passage has a small diameter section and a large diameter section that is positioned in the return direction more than the small diameter section and has a larger diameter than the small diameter section. The large-diameter portion is provided with a flow rate variable mechanism for adjusting the flow rate of oil in the oil passage. The aforementioned variable flow rate mechanism is A support member is installed in an immovable state in the aforementioned oil passage and has a disc portion and a cylindrical portion extending from the outer peripheral edge of the disc portion in the return direction, An orifice member that is displaced in the return direction and the forward direction inside the cylindrical portion, The orifice member is provided with a spring that biases it in the forward direction, A groove extending in the return direction is formed on the inner circumferential surface of the cylindrical portion. The orifice member has a ring-shaped body and a projection that protrudes radially outward from the outer circumference of the body and is housed in the groove. The groove and the projection are configured to prevent the orifice member from tilting with respect to the axis of the cylindrical portion. A clutch device characterized by the following features.

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