JPH0725284B2 - Walk-type work machine operation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an operation for adjusting a traveling speed in a working machine for performing lawn mowing, mowing, snow removal, and other work while moving according to the walking speed of an operator. Regarding the improvement of the device.

(Prior Art) In this type of working machine, as shown in Japanese Patent Application Laid-Open No. 61-96223 or Japanese Patent Application No. 62-134191 filed by the applicant of the present invention, a power source for starting and stopping the working machine is used. The transmission is provided with a member that transmits and cuts off and a member that performs a gear shift operation to change the traveling speed, and a traveling lever along the grip and a gear shift lever at a different position are pivotally installed on the handle for operation to shift gears. Each member of the machine and each lever are connected by a wire so that both members can be operated independently.

(Problems to be Solved by the Invention) In the above-mentioned conventional technique, since both the traveling lever and the gear shift lever may be operated during traveling, both hands must be used, and when the gear shift lever is in the high speed position. If you try to start, you may receive a shock when you start moving.

In addition, the handle has a lever and wire for operating the work machine,
Since the throttle lever, the wire, and the like must be provided, if the wire is connected to each of the traveling lever and the shift lever, the steering wheel becomes complicated and lacks simplicity.

(Means for Solving the Problem) The present invention solves these problems, and the first means is, as described in claim 1, an engine and a vehicle body provided with a handle for operation on the upper part thereof. A lever in which a hydraulic transmission driven by an engine and a working device are mounted, a wheel is driven by the hydraulic transmission, and a neutral valve for releasing the hydraulic circuit thereof and a shift operation shaft are pivotally attached to the handle. In a walk-behind work machine operating device that is operated by a wire and a wire connected thereto, a traveling lever is pivotally attached near the grip of the handle, and a gearshift lever is pivotally attached to the traveling lever, and the neutral valve and the gearshift operation are performed. The arm of the shaft is connected and connected to one speed change wire, the pin attached to the tip of the speed change wire is locked to the travel lever by the speed change lever, and the travel lever is returned by the return spring. The feature is that it is biased away from the handle grip.

A second means is, as described in claim 2, in claim 1, a hydraulic transmission is constituted by a variable displacement pump and an oil motor, and a shift operation shaft for controlling a discharge amount of the variable displacement pump and a hydraulic pressure. A neutral valve capable of releasing the circuit is provided, and the gear shift operation shaft and the neutral valve are closed when the gear shift operation shaft is in the neutral position, and the neutral valve is closed when the gear shift operation shaft is rotated in the speed increasing direction. It is characterized by interlocking to maintain.

(Operation) Since the above-mentioned means are provided, when the travel lever is gripped with the handle, the neutral valve is first closed to enable transmission of the hydraulic transmission, and then the shift operation shaft is shifted from the neutral position or the low speed position to the speed increasing direction. Therefore, the vehicle is started at a low speed. When the speed change lever is operated, the degree of tension of the operation wire is changed, and the speed change operation shaft is rotated irrespective of the travel lever to change the travel speed.

(Examples) Examples will be described below with reference to the drawings. 1 and 2, 1 is a work machine for lawn mowing, 2 is a vehicle body, 3 is an engine, 4 is a hydraulic transmission, 5 is a front wheel, 6 is a rear wheel, and the rear wheel 6 is from the engine 3. It is driven via the shaft 7 and the hydraulic transmission 4, and the cutting blade 8 is directly driven by the engine 3.

A U-shaped operating handle 9 having a grip 9a extends from the rear of the vehicle body 2 upward and obliquely rearward, and a U-shaped traveling lever 10 is pivotally attached to the upper portion of the handle 9 by a pin 11. A gear shift lever 14 for locking the tip of the gear shift wire 13 to a bracket 12 provided near the pin 11 and changing the locking position is pivotally attached to the bracket 12 by a pin 15.
Also, 16 is a throttle lever, 17 is a cutting blade operation lever, 17
a is an operation wire.

As shown in FIG. 3, a bifurcated bracket 12 is continuously provided on the traveling lever 10, and an adjustment groove formed in the bracket 12
18 waveform engaging surface 18a is provided, to which are anchored the pin 13a ₁ is engaged passing through the tip 13a of the control cable, the slot 14a of the shift lever 14 to the pin 13a ₁ is engaged.

The pin 13a ₁ is the distance from the pin 11 by the lever 14 from l ₁
It can be changed up to l _2, and the larger the distance, the larger the amount of wire pulling when the speed change lever 10 is turned upward.

The shape of the adjustment groove 18 may be an arc shape or may have an appropriate inclination angle with respect to the traveling lever 10.

The hydraulic transmission 4 is shown in the lower half of FIG. 2 and FIGS. 4 (a) and 4 (b).
And a speed reducer 24 having a variable swash plate type oil pump 20 driven by the shaft 7 from the engine, an oil motor 21, a pinion 22 driven by the oil motor 21, and a gear 23. The rear wheel 25 is driven.

The oil pump 20 is well known and includes a drive shaft 26, a cylinder block 27, and a swash plate 28, and the discharge amount is changed by rotating the swash plate 28 around a shaft line 28a by a speed change shaft 29. The oil motor 21 whose details are omitted is also well known, and includes a swash plate,
It has a cylinder block and is rotated by the hydraulic pressure sent from the oil pump 20 through the hydraulic circuit 34 as shown in FIG. 5, thereby driving the pinion 22. Is provided outside the circuit to deactivate the hydraulic transmission 4. A neutral valve 30 is provided.

Then, as shown in the lower half of FIG. 2, the speed change arm 31 is fixed to the speed change shaft 29, the neutral arm 32 is fixed to the neutral valve 30, and both arms 31, 32 are linked by the interlocking rod 33 to form the speed change arm. The speed change wire 13 is connected to the other end of 31. Then, each arm is pulled by the return spring 34 to retract the speed change operation shaft 29 and the neutral valve 30 to the inoperative neutral position. In this state, the oil pump 20 rotates, but has no pumping action, and the hydraulic circuit is open.

FIG. 5 conceptually shows the operation of each part of the hydraulic transmission 4. When no tension is applied to the speed change wire 13, as shown in FIG. 5 (a), the hydraulic circuit 34 includes a neutral valve. 30
Of the pump 20, the inclination angle of the swash plate 28 of the pump 20 is set to a slightly negative angle, the oil slightly flows backward from the valve 30, but the motor 21 does not operate and the vehicle is stopped. . When the traveling lever 10 is grasped together with the grip 9a of the handle 9 and pushed toward the grip 9a, the wire 13 is pulled and the flow path of the neutral valve 30 is almost closed as shown in FIG. 5 (b). The inclination angle of the swash plate 28 of the oil pump 20 is 0 (neutral)
Then, the oil operation is stopped, the oil motor 21 is not driven, and the neutral state is maintained, and the vehicle remains stopped.

When the travel lever 10 is further pushed to reach FIG. 5 (c), the hydraulic circuit 34 is completely closed, the rotation of the speed change shaft 29 and the inclination angle of the swash plate 28 are increased, and the discharge amount is also changed according to the inclination angle. The number of wheels 6 is increased and the wheels 6 are sequentially accelerated. In this way, since the gear ratio gradually increases from the neutral state, even if the gear shift lever 14 is shifted to the high speed side, there is no sudden start and less shock is given to the drive system.

5 (a) and (b), when the vehicle is stopped, the traveling width of the traveling lever 10 is set to be large, so that the vehicle can be started at a very low speed.

Although a rotary type valve is shown as the neutral valve 30,
A linear motion type valve may be used.

When the user wishes to shift gears while traveling, the gripping of the traveling lever 10 may be adjusted, or the gear shift lever 14 may be shifted by grasping the lever 10 in contact with the grip 9a.

Although the lawnmower has been described above, it can be similarly applied to a snow removing work machine.

(Effects of the Invention) According to the present invention, since the neutral valve and the gear shift operation shaft are operated by the traveling lever as described above, the vehicle is started from the neutral state via the gear ratio of the low speed drive, and always starts at the low speed. It is also possible to run at a very low speed.

Further, since the speed can be adjusted by grasping the traveling lever, it is convenient that another work can be performed with one hand while traveling at a variable speed. In addition, it is possible to adjust the speed by operating the speed change lever by grasping the traveling lever in contact with the handle or making an appropriate angle, so change the way of grasping the handle and the traveling lever. Fine adjustment can be done easily.

Further, since the traveling lever and the shift lever are connected to one wire, there is an effect that the steering wheel is simplified.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention, FIG. 2 is a perspective view of an essential part, FIG. 3 (a) is a plan view of a shift lever, (b) is a side view, and FIG. 4 (a) is FIG. 5A is a vertical sectional view of the hydraulic transmission, FIG. 5B is a horizontal sectional view, and FIGS. 5A, 5B, and 5C are operation explanatory views. 4 …… hydraulic transmission, 9 …… handle 10 …… travel lever, 13 …… shift wire 13a …… tip, 14 …… shift lever 29 …… shift operating shaft, 30 …… neutral valve 31 …… shift operating arm 32 …… Neutral arm

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 54-65928 (JP, A) JP 54-64328 (JP, A) Actual development 61-183739 (JP, U) JP 49- 17878 (JP, Y1)

Claims (2)

[Claims] 1. An engine (3), a hydraulic transmission (4) driven by the engine (3), and a working device are mounted on a vehicle body (2) having an operating handle (9) on the upper portion thereof. A neutral valve (30) for driving wheels by a hydraulic transmission (4) and releasing the hydraulic circuit thereof and a gear shift operation shaft (29) are connected to a lever pivotally attached to the handle (9) and the lever. In a walk-behind work machine operating device adapted to be operated with a wire, a traveling lever (10) is pivotally attached near a grip (9a) of a handle (9), and the traveling lever (10) is provided with a speed change lever (14). ) Is pivotally attached, and the neutral valve (30) and the arms (32) (31) of the speed change operation shaft (29) are connected to connect to one speed change wire (13), and at the tip of the speed change wire (13). The attached pin (13a ₁ ) is locked to the travel lever (10) so that the position can be adjusted by the speed change lever (14). And running lever (10)
The grip (9a) of the handle (9) with the return spring (34)
A walk-behind work machine operation device characterized by being urged in a direction away from the work machine. 2. The variable displacement pump (20) according to claim 1.
A hydraulic transmission (4) is configured by the oil motor (21) and the oil motor (21), and the gear shift operation shaft (29) for controlling the discharge amount of the variable displacement pump (20) and the neutral circuit (34) capable of releasing the hydraulic circuit (34).
0) valve is provided, and the speed change operation shaft (29) and the neutral valve (30) are closed. When the speed change operation shaft (29) is in the neutral position, the neutral valve (30) is closed and the speed change operation shaft (29) is moved. A walk-behind work machine operating device characterized in that the neutral valve (30) is interlocked so as to maintain a closed position when it is rotated in an ascending direction.