JPS6288824A - Hydraulic clutch operating device for running vehicle - Google Patents

Abstract

PURPOSE:To simplify the structure and to soften a shock at the time of starting at a low price by interlocking an operating member with a piston in such a manner that when the operating member is operated, the piston slides in the direction of releasing spring pressure. CONSTITUTION:A pressure regulating valve 43, an orifice valve 44 and a directional control valve are incorporated in a valve main body 45, which is selectively connected to a pump port 47, a drain port 48, a forward clutch port 49 and a backward clutch port 50 by the movement of a spool 46. The pressure regulating valve 43 includes a valve element 52, a piston 53, spring 54, 55 and a rod 40. The valve element 52 is adapted to open and close a drain port 57. When the operating pedal is stepped on in the running condition where the piston 53 is brought into contact with a step portion 58, the piston 53 is pulled back through a lever 37and the rod 40, so that operating oil pressure is decreased with the spring pressure to disconnect a clutch. Accordingly, it is not necessary to provide another valve, so that the structure is simplified and at the time of starting, a shock is softened.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a hydraulic clutch operating device for running a vehicle, and is capable of turning on and off a hydraulic clutch by operating a pressure regulating valve. .

(Prior art) The forward/reverse switching device installed in the running system of a vehicle such as a tractor is of a hydraulic clutch type, and the hydraulic clutch is controlled by switching the forward/reverse switching valve, while a pressure regulating valve is installed in the hydraulic circuit. By sliding the piston of this regulating valve against a spring, the pressure of the hydraulic oil supplied to the hydraulic clutch is gradually increased, and the shock at the time of starting is alleviated. be.

In this type of device, when manually disconnecting the hydraulic clutch without operating the switching valve, conventionally a third valve that is linked to pedal operation is provided in addition to the switching valve and the pressure regulating valve.
This is done using a valve.

(Problems to be Solved by the Invention) However, providing the third valve in this manner causes various problems in implementation, such as the structure becoming more complicated and the manufacturing cost increasing.

(Means for Solving the Problems) The present invention has been provided for the purpose of solving such conventional problems, and as a means for that purpose, the present invention includes the following in the control system of the hydraulic clutch for traveling. A pressure regulating valve is provided separately from the switching valve that controls the switching of the hydraulic clutch, and by sliding the piston of this pressure regulating valve against a spring, the pressure of the hydraulic oil supplied to the hydraulic clutch is gradually increased. In such a device, an operating member is provided, and the operating member and the piston are interlocked so that the piston slides in the spring pressure release direction when the operating member is operated.

(Function) When starting, the piston 53 of the pressure regulating valve 43 slides to the right in FIG. 4 while resisting the springs 54 and 55, and the pressure of the hydraulic oil gradually increases.

While the vehicle is running, the piston 53 is in contact with the stepped portion 58. Therefore, when the operating pedal 31 is depressed, the rod 40 slides along with the piston 53 to the left in FIG. It goes down and the hydraulic clutch disengages.

(Embodiment) The present invention will be described in detail below with reference to the illustrated embodiment.
In the drawings and FIG. 2, reference numeral 2 denotes a tractor body, which is composed of a transmission case 2 and the like, and a rear axle case 4 protrudes from both sides of the rear part of the transmission case 2 via a brake case 3. Reference numeral 5 denotes a hydraulic device for lifting and lowering the work machine, which has a pair of left and right lift arms 6.

Reference numeral 8 denotes a pair of left and right rear wheel fenders that cover the rear wheels. A floor seat 9, a seat 10, and a fuel tank 1) are arranged between the pair of fenders 8, and the left and right rear wheel fenders 8 cover the rear wheels. A pair of steps 12 are arranged. Further, the mid-height portions of the front parts of both fenders 8 are connected by a front cross beam member 13, and the upper and lower ends of the rear parts of both fenders 8 are connected by rear upper and rear lower cross beam members 14 and 15, respectively. .

The fuel tank 1) is located on the rear side of the seat 10 above the hydraulic device 5, and has a width slightly smaller than the distance between the fenders 8, so that the rear portion of the fenders 8 is closed. The fuel tank 1) has a joining flange l located approximately in the center in the longitudinal direction.
la is fixed to the rear upper and rear lower cross beam members 141) 5 with bolts. Fuel tank 1) Fuel supply port 16 on the top surface
protrudes diagonally upward at the rear. In the rear wall portion 17 of the fuel tank 1), a recessed portion 18 is formed in the shape of a long band in the horizontal direction, and a display portion 1 for displaying a company name mark etc. is formed within the four portions 18 of the recessed portion 18.
9 is formed in a protruding shape. Therefore, fuel tank 1)
Even when the divided body is press-formed from a sheet metal material, rigidity can be ensured by the unevenness of the concave portion 18 and the display portion 19.

Inside the mission case 2 is the engine 2 as shown in Figure 3.
A running system 21 that transmits power from zero to the rear wheels and a PTO system 23 that transmits power to a PTO shaft 22 are incorporated. The traveling system 21 includes a traveling propulsion shaft 24, a hydraulic clutch type forward/reverse switching device 25, a transmission 26, a differential device 27, etc., and the PTO system 23 includes a PTO propulsion shaft 28, a transmission 29, etc.

Reference numeral 30 denotes a forward/reverse switching valve for controlling the forward/reverse switching device 25, which is attached to the tractor body 1 side.

Reference numeral 31 denotes an operating pedal, which is pivotally supported on the step 12 via a pedal shaft 32 and positioned by a spring 34 connected to a link 33 and a strike collar 35. The link 33 is connected to a rear operating lever 37 via a rod 36, and the operating lever 37 is pivotally supported to the step 12 by a support shaft 38, and the fork portion 39 at the upper end is connected to the switching valve 30.
It is possible to engage with the engagement pin 41 of the side rod 40.

The switching valve 30 is incorporated into a valve body 45 together with a pressure regulating valve 43 and an orifice valve 44, as shown in FIGS. 4 and 5. The switching valve 30 has a spool 46 rotatably inserted into the valve body 45, and by rotation of the spool 46, the pump port 47, drain port 48, forward clutch port 49, and reverse clutch port 50 are selectively connected. Connecting. One end of the spool 46 penetrates a cover 50 attached to the valve body 45 and projects outward, and a lever 51 is provided at the projecting end.

The lever 51 can be positioned at neutral, forward, and reverse positions by a positioning mechanism.

The pressure regulating valve 43 includes a valve body 52 that is disposed so as to be slidable in the axial direction facing the spool 46 of the switching valve 30, and this valve body 5.
2, a piston 53 is disposed to be slidable in the axial direction on the opposite side of the spool 46, and this valve body 52 and the piston 5
The piston 53 includes two large and small springs 54 and 55 which are interposed between the valve body 52 and the piston 53 and are concentric with each other, and a loft 40 that regulates the distance between the valve body 52 and the piston 53.

The valve body 52 is provided to open and close the drain port 57. The sliding range of the piston 53 is restricted by a stepped portion 58, and the outer spring 55 of the two large and small springs 54 and 55
is longer than the inner spring 54.

The rod 40 is fixed to the piston 53 and protrudes forward through the cover 59 in a slidable manner, and an engagement pin 41 is provided at the front end of the rod 40 . Therefore, when the operating pedal 31 is depressed, the operating lever 37 rotates, the fork portion 39 engages with the engagement pin 41, and the piston 53 can be operated via the rod 40 in the direction in which the springs 54 and 55 are biased. It looks like this. Note that the distance LI between the fork portion 39 and the engagement pin 41 is equal to or slightly larger than the stroke L2 of the piston 53.

The orifice valve 28 is provided in the middle of oil passages 43 and 44 formed in the valve body 29 and a cover 42 to which the valve body 29 is removably attached, in order to communicate between the pump port 31 side of the switching valve mechanism 9 and the back of the piston 36. It is mediated. Orifice valve 28
As shown in FIG. 3, a plurality of orifice holes 46 with different diameters are formed in the circumferential direction in a disc-shaped valve body 49 fixed to the inner end of a rotating shaft 45. 45 is cover 4
2 so that it can be rotated and operated from the front.

Next, the effect will be explained. At the time of forward/reverse switching, the switching valve 30 is operated by a forward/reverse switching lever (not shown).

Now, if the switching valve 50 is switched to the forward side as shown by the imaginary line in FIG. It resists and is pushed to the left in FIG. 4, and flows to the drain port 57. On the other hand, since hydraulic oil is supplied to the rear of the piston 53 through the oil passage 61 and the flow rate is appropriately restricted by the orifice valve 44, the piston 53 slides to the right in FIG. 4 until it comes into contact with the stepped portion 58. move. During this time, the piston 53 compresses the spring 55 and then further compresses both springs 54 and 55, so the valve body 52 throttles the drain port 57, and the circuit pressure of the forward clutch port 49 has a large gradient midway. It rises due to its boosting characteristics. When the piston 53 comes into contact with the stepped portion 58, the valve body 52 is held in contact with the rod 40. This action connects the forward clutch and starts the vehicle, so the shock at the time of starting can be alleviated and the vehicle can start quickly.

When the forward clutch is connected, the piston 53 moves toward the stepped portion 5.
At this time, the engagement pin 41 of the rod 56
is located near the pole of the fork portion 39 of the operating lever 37. Then, when the operation pedal 31 is depressed, the link 3
3. The operating lever 37 rotates around the support shaft 38 via the rod 36, the fork portion 39 engages with the engagement pin 41, and the piston 53 is pulled back to the left in FIG.

Therefore, the springs 54 and 55 are both released from the compressed state, and the spring pressure acting on the valve body 52 rapidly decreases, so that the valve body
2 opens the drain hole 57, hydraulic oil from the pump boat 47 escapes to the drain port 57, the pressure drops rapidly, and the forward hydraulic clutch is disengaged. Therefore, the operating pedal 31
By depressing , the hydraulic clutch can be disengaged even if the switching valve 30 is on the forward side.

If the pressing force on the operating pedal 31 is suddenly released, the fork portion 39 separates from the engagement pin 41, so the pressure regulating valve 43 operates in the same way as described above, allowing smooth start. Furthermore, if the pedal force is gradually released, the piston 53 will operate accordingly.
It is also possible to boost the voltage more slowly than the original boosting characteristic.

Note that instead of the operating pedal 31, a lever may be provided as an operating member and manually operated.

(Effects of the Invention) According to the present invention, when an operation is performed, the piston of the pressure regulating valve slides in the spring pressure release direction in conjunction with the operation, so that the switching valve is held in the clutch connected state and the hydraulic pressure is The clutch can be disengaged, and therefore it is structurally simpler and cheaper to implement than the conventional method which requires a separate valve.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a cross-sectional side view of the rear of the tractor, Fig. 2 is a cross-sectional rear view of the same, Fig. 3 is a configuration diagram of the transmission system, and Fig. 4 is a cross-section of the forward switching valve. Figure 5 is the 4th
It is a VV arrow view of a figure. 25... Forward/forward switching device, 30... Forward/forward switching valve,
31... Operation lever, 37... Operating lever, 40.
...Lot, 43...Pressure regulating valve, 53...Piston, 54.55...Spring.

Claims (1)

[Claims] (1) In the control system of the hydraulic clutch for traveling, a pressure regulating valve is provided separately from the switching valve that controls switching of the hydraulic clutch, and by sliding the piston of this pressure regulating valve against a spring, the hydraulic clutch In a system that gradually increases the pressure of hydraulic oil supplied to A hydraulic clutch operating device for driving a vehicle, characterized in that: