JP3559108B2 - Hydraulic clutch - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a hydraulic clutch.
[0002]
[Prior art]
Conventionally, there is a hydraulic clutch that generates frictional force by hydraulic pressure and transmits power through the frictional force. In particular, a cylinder formed on a clutch shaft by receiving the above hydraulic pressure has a small operating force. Since the clutch operating mechanism can be configured compactly, it is often used in a clutch or the like provided inside a transmission such as a work vehicle having a large power.
[0003]
[Problems to be solved by the invention]
However, in the above-mentioned hydraulic clutch, when the power transmission is connected, the hydraulic pressure suddenly acts to start the power transmission in a shocking manner, so that the machine body is shocked or a large torque is applied to the drive system, and the load of the load is reduced. If the inertia is large, there is a problem that the drive system is damaged.
[0004]
[Means for Solving the Problems]
In the present invention, inner and outer drums are respectively connected to the clutch input shaft and the clutch output shaft, and the clutch plate and the friction plate respectively engaged with the inner and outer drums are alternately layered to form a friction body, In a hydraulic clutch configured to transmit power by pressing a friction body, a large-diameter cylinder opened in the friction body direction is formed on the outer drum, and a large-diameter piston is fitted into the large-diameter cylinder, inside to form an open small diameter cylinder friction body direction, by fitting the small-diameter piston in the small cylinder, and a large-diameter oil chamber formed in the large diameter cylinder and the large piston, a small-diameter cylinder and a small-diameter piston a small diameter oil chamber formed by the, and can communicate with the hydraulic pressure source, further than the end of the large diameter piston end portion of the small-diameter piston allowed protruding friction body direction, the large-diameter oil chamber and a small-diameter oil When the hydraulic pressure acts on the friction plate, the end of the small-diameter piston is first brought into contact with the pressure plate to apply a pressing force to the friction body, and then the end of the large-diameter piston is brought into contact with the pressure plate. A hydraulic clutch characterized in that a pressing force is applied to the hydraulic clutch.
[0005]
【Example】
Embodiments of the present invention will be described with reference to the drawings.
[0006]
1 and 2 show an agricultural tractor A as a working vehicle equipped with a hydraulic clutch G according to the present invention. The tractor A has a three-point link of various working machines such as a rotary tilling work machine B at the rear. It is connected so as to be able to move up and down by a lifting mechanism C of a type so that work by various working machines can be performed.
[0007]
In the agricultural tractor A, a vehicle body frame 3 is suspended between traveling frames 2 and 2 of a pair of left and right crawler-type lateral traveling devices 1 and 1, and a motor unit 4 is mounted on a front portion of the vehicle body frame 3. The cabin 5 is mounted on the rear part, the seat 6 is disposed inside the cabin 5, and the operation part M is provided on the floor F in front of the seat 6.
[0008]
An engine E is disposed in the prime mover unit 4, and a traveling transmission 10 for driving the left and right traveling devices 1, 1 is interlocked to the engine E, and various working machines such as the rotary plowing work machine B are provided. In order to drive the PTO front transmission 12 and the PTO rear transmission 13, the hydraulic clutch G of the present invention is provided inside the PTO front transmission 12 in the present embodiment. ing.
[0009]
As shown in FIGS. 3 and 4, the PTO front transmission 12 and the hydraulic clutch G are connected via a meshing gear 16 with the rear end of an engine output shaft 15 extending from the engine E inside the casing 14 of the PTO front transmission 12. And a clutch output shaft 21 interlockingly connected to the PTO rear transmission 13 via a counter shaft 18, a universal joint 19, and an external intermediate shaft 20. A two-speed transmission mechanism 22 is formed between the shaft 21 and the counter shaft 18.
[0010]
A concave portion for fitting the pilot bearing 23 is formed on the rear end surface of the clutch input shaft 17. A convex portion formed at the front end of the clutch output shaft 21 is inserted into the pilot bearing 23 to The clutch output shaft 21 is located on the virtual extension line of the shaft center.
[0011]
At the rear end of the clutch input shaft 17, the central portion of the inner drum 24 having a large number of axial grooves formed on the outer peripheral surface is externally fitted non-rotatably, while fitted around the central portion of the outer side drum 27 formed many axial grooves on the surface first half, between the inner drum 24 peripheral surface and the outer side drum 27 inner peripheral surface, the inner drum 24 peripheral surface a clutch plate 25 which is fitted to the groove, and disposed an outer side friction plates fitted inside the drum 27 to the groove of the circumferential surface 26 and the friction member 28 formed by layered alternately.
[0012]
In FIG. 3, P is a hydraulic pump, HST is a hydrostatic transmission for driving, 13a is a two-stage transmission mechanism provided in the PTO rear transmission 13, 13b is a PTO output shaft, and 19a is a coupling. Reference numerals 29, 30 denote a retaining ring and a retainer for preventing the friction body 28 from moving forward. Reference numeral 31 denotes a pressure plate for transmitting a pressing force of a piston described later to the friction body 28.
[0013]
Further, the inner peripheral surface half portion of the outer side drum 27 and the large-diameter cylinder 32 is formed, between the inner and size diameter cylinder 32 peripheral surface and the clutch output shaft 21 peripheral surface, the rear direction with a large spring 33 The large-diameter piston 34, which is urged to the cylinder 35, is slidably fitted in the axial direction, and a small-diameter cylinder 35 that opens forward is formed inside the large-diameter piston 34. A small-diameter piston 38 urged forward by a small spring 37 is fitted between the central portion of the diameter piston 34 and an outer peripheral surface of a boss portion 36 formed by extending forward.
[0014]
The large-diameter oil chamber 39 formed by the large-diameter cylinder 32 and the large-diameter piston 34 communicates with the common oil passage 41 through which the clutch output shaft 21 is inserted in the axial direction through the large-diameter oil passage 40, The small-diameter oil chamber 42 formed by the small-diameter 35 and the small-diameter piston 38 communicates with the common oil passage 41 via the small-diameter oil passage 43, and the common oil passage 41 is interlocked with a PTO clutch lever 44 provided in the operation unit M. It is connected to the hydraulic pump P via the connected PTO control valve 45. In FIG. 4, 47 and 48 are retaining rings and spring retainers for locking the front end of the large spring 33, 49 is a stopper for regulating the forward movement of the small-diameter piston 38, and 50 is an O-ring.
[0015]
Therefore, when the hydraulic pressure is not acting on the large-diameter oil chamber 39 and the small-diameter oil chamber 42, the large-diameter piston 34 moves backward by the bias of the large spring, and the small-diameter piston 38 moves forward by the small spring 37. Although being urged, the stopper 49 restricts the forward movement with respect to the large-diameter piston 34, and in this state, the front end 52 of the small-diameter piston 38 projects forward from the front end 53 of the large-diameter piston 34.
[0016]
With this configuration, when the PTO clutch lever 44 is operated in the OFF direction, the oil path of the PTO control valve 45 is switched to release the hydraulic pressure of the common oil path 41, and the large-diameter piston 34 and the small-diameter piston Since the front ends 52 and 53 of 38 are separated from the pressure plate 31 and no pressing force acts on the friction body 28, the hydraulic clutch G is disengaged.
[0017]
When the PTO clutch lever 44 is operated in the ON direction, the oil path of the PTO control valve 45 is switched, the hydraulic pressure from the hydraulic pump P passes through the common oil path 41, and the large-diameter piston 34 and the small-diameter piston 38 move forward. The front end of the small-diameter piston 38 projecting forward from the front end of the large-diameter piston 34 applies a pressing force to the friction body 28 via the pressure plate 31 to transmit power. Since the outer diameter is smaller than the outer diameter of the large-diameter piston 34, the internal oil pressure of the small-diameter oil chamber 42 becomes higher than the internal oil pressure of the large-diameter oil chamber 39, that is, the oil pressure of the common oil passage 41. Pressure oil flows out to the common oil passage 41, and the small-diameter piston 38 moves backward with respect to the large-diameter piston 34.
[0018]
This state continues until the front end of the large-diameter piston 34 comes into contact with the pressure plate 31. Thus, from the time when the hydraulic pressure starts to act, the pressure plate 31 is first pressed with a small force by the small-diameter piston 38 to engage the half-clutch state. Appears, and this state is maintained for the duration described above. Then, the pressure plate 31 is pressed by the large force of the large-diameter piston 34, and complete power transmission without clutch slippage is performed. Transmission start can be performed.
[0019]
When the PTO clutch lever 44 is operated in the OFF direction to close the PTO control valve 45, the large-diameter piston 34 and the small-diameter piston 38 are retracted integrally by the bias of the large spring 33 and separated from the pressure plate 31. Then, the pressing force on the pressure plate 31 is released, and then the small-diameter piston 38 moves forward by the urging of the small spring 37 to return to the initial state in which the power transmission of the hydraulic clutch G is cut off.
[0020]
As described above, the large-diameter piston 34 and the small-diameter piston 38 are integrally separated from the pressure plate 31 to release the pressing force, so that the half-clutch state does not appear and the hydraulic clutch G can be instantaneously disengaged.
[0021]
Further, by adjusting the ratio of the inner diameter of the large-diameter oil passage 40 to the inner diameter of the large-diameter piston 34 and the ratio of the inner diameter of the small-diameter oil passage 43 to the inner diameter of the large-diameter piston 34, the characteristics of the half-clutch are improved. Can be adjusted.
[0022]
FIG. 5 shows that when the agricultural tractor A having the driving sprocket mounted on the front portion of the traveling device is moved backward, the portion located above the crawler belt 61 surrounding the outer periphery of the traveling device is relaxed and the crawler belt comes off. This shows a hydraulic crawler belt tensioning device 62 for prevention, in which a pivot 63 is protruded horizontally on the traveling frame, and a central portion of a substantially L-shaped tension lever 64 is pivotally attached to the pivot 63 so as to be rotatable. The upper idler 65 is rotatably supported at the upper end of the tension lever 64, and the piston rod 67 of the tension hydraulic cylinder 66 is pivotally attached to the lower end of the tension lever 64. M is connected to the hydraulic pump P via a tensioning device control valve 69 interlocked with a forward / reverse switching lever 68 disposed at M. 73 is a stopper for restricting the downward movement of the upper idler 65.
[0023]
Further, a check valve 71 that allows the pressurized oil to flow only in the direction of the tension hydraulic cylinder 66 between the tension device control valve 69 and the tension hydraulic cylinder 66, and the hydraulic pressure in the tension hydraulic cylinder 66 becomes equal to or higher than a predetermined pressure. And a relief valve 72 that can release the same hydraulic pressure manually and in parallel.
[0024]
Therefore, when the forward / reverse switching lever 68 is operated in reverse, hydraulic pressure is supplied to the tension hydraulic cylinder 66 via the tension device control valve 69, and the piston rod 67 of the tension hydraulic cylinder 66 is extended, so that the tension lever 64 By moving the upper idler 65 upward through the torsional tension of the upper part of the crawler belt 61 that relaxes during reverse movement, the crawler belt can be prevented from coming off.
[0025]
Further, since the check valve 71 is provided between the tension hydraulic cylinder 66 and the tension device control valve 69, the hydraulic pressure remains in the tension hydraulic cylinder 66 even if the forward / reverse switching lever 68 is switched to the forward direction. , Can keep track tension.
[0026]
Further, by manually opening the relief valve 72, the tension of the crawler belt by hydraulic pressure is released, and the work of adjusting the crawler belt tension by, for example, a screw type or a grease-up type can be performed.
[0027]
【The invention's effect】
In the present invention, inner and outer drums are respectively connected to the clutch input shaft and the clutch output shaft, and the clutch plate and the friction plate respectively engaged with the inner and outer drums are alternately layered to form a friction body, In a hydraulic clutch configured to transmit power by pressing a friction body, a large-diameter cylinder opened in the friction body direction is formed on the outer drum, and a large-diameter piston is fitted into the large-diameter cylinder, inside to form an open small diameter cylinder friction body direction, by fitting the small-diameter piston in the small cylinder, and a large-diameter oil chamber formed in the large diameter cylinder and the large piston, a small-diameter cylinder and a small-diameter piston a small diameter oil chamber formed by the, and can communicate with the hydraulic pressure source, further than the end of the large diameter piston end portion of the small-diameter piston allowed protruding friction body direction, the large-diameter oil chamber and a small-diameter oil When the hydraulic pressure acts on the friction plate, the end of the small-diameter piston is first brought into contact with the pressure plate to apply a pressing force to the friction body, and then the end of the large-diameter piston is brought into contact with the pressure plate. When the hydraulic pressure starts to act on the hydraulic clutch and power transmission starts, first, the tip of the small-diameter piston presses the frictional body with a small force to display the half-clutch state. Out, and then the large-diameter piston presses the frictional body with a large force to achieve complete power transmission without clutch slippage.
[0028]
Therefore, the start of power transmission is performed gently, and it is possible to prevent shock due to rapid power transmission and damage to the engine, load drive system, and the like connected to the hydraulic clutch.
[Brief description of the drawings]
FIG. 1 is a side view of an agricultural tractor provided with a hydraulic clutch according to the present invention.
FIG. 2 is a plan view of the tractor.
FIG. 3 is an explanatory diagram showing a configuration of a traveling transmission.
FIG. 4 is a sectional side view showing a configuration of the hydraulic clutch.
FIG. 5 is a schematic explanatory view showing a configuration of a hydraulic crawler belt tensioning device.
[Explanation of symbols]
G Hydraulic clutch 17 Clutch input shaft 21 Clutch output shaft 25 Clutch plate 24 Inner drum 26 Friction plate 27 Outer drum 28 Friction body 32 Large diameter cylinder 34 Large diameter piston 35 Small diameter cylinder 38 Small diameter piston 39 Large diameter oil chamber 42 Small diameter oil chamber

Claims (1)

Inner and outer drums (24) and (27) are respectively connected to the clutch input shaft (17) and the clutch output shaft (21), and the clutch plates (25) engaged with the inner and outer drums (24) and (27), respectively. And a friction plate (26) alternately layered to form a friction body (28), and a hydraulic clutch (G) configured to transmit power by pressing the friction body (28) with hydraulic pressure,
Friction body outer side drum (27) (28) forms a large-diameter cylinder (32) which opens in the direction, and fitting the large-diameter piston (34) to the university diameter cylinder (32), the large-diameter piston (34 ) to form an inner friction member (28) diameter cylinder which is open in the direction (35) of, and fitted into the small-diameter piston (38) in the small-diameter cylinder (35), and the large diameter cylinder (32) diameter piston (34) and a large-diameter oil chamber (39), and a small-diameter oil chamber (42) formed by a small-diameter cylinder (35) and a small-diameter piston (38) can be connected to a hydraulic pressure source ,
Furthermore, the end of the small-diameter piston (38) is made to protrude toward the friction body (28) from the end of the large-diameter piston (34) , and hydraulic pressure is applied to the large- diameter oil chamber ( 39) and the small-diameter oil chamber (42). When this occurs, the end of the small-diameter piston (38) is first brought into contact with the pressure plate (31) to apply a pressing force to the friction body (28) , and then the end of the large-diameter piston (34) is pressured. A hydraulic clutch, characterized in that it is configured to contact a plate (31) to apply a pressing force to a friction body (28) .

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