JPH0613912B2 - Switching device for traveling pedal of wheel type working vehicle - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel type working vehicle, and relates to a one-way foot operation type running pedal device.

2. Description of the Related Art FIG. 10 is a diagram showing a configuration of a side surface and a variable hydraulic pump control of a conventional traveling pedal device of a wheel type work vehicle, in which 1 is a driver's seat, 2 is a support plate, and 3'is a traveling pedal.
4'and 5'are rods, 6'is a bell crank, 7 is a variable hydraulic pump, and 8 is a traveling motor. Therefore, when the driver depresses the front side a position or the rear side position of the traveling pedal 3'from the neutral position N of the traveling pedal 3 ', the variable hydraulic pump 7
The control lever 9 rotates from the neutral position N'to the a position or the b position. As a result, the pressure oil discharged from the variable hydraulic pump 7 causes the traveling motor 8 to rotate in the forward or reverse direction via the oil passage 22 or the oil passage 23, so that the work vehicle moves forward or backward. Next, in the traveling pedal device shown in FIG. 11 as another embodiment of the prior art, when the traveling pedal 3'is depressed from the neutral position N to the front side a position or the rear side b position of the traveling pedal 3 '. Spool 2 of switching valve 24
5 switches from the neutral position N'to the C position or the D position.
As a result, the hydraulic fluid discharged from the hydraulic pump 26 passes through the oil passage 22 or the oil passage 23 to operate the traveling motor 8 in the forward or reverse direction, so that the work vehicle moves forward or backward.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In a hydraulically driven wheel-type work vehicle, a control lever of a variable hydraulic pump or a spool of a switching valve is actuated by stepping on a foot-operated traveling pedal, and a pump inclination angle or switching of the variable hydraulic pump is operated. The stroke amount of the valve spool is controlled to control the rotation direction and the rotation speed of the traveling wheels driven by the traveling motor so that the work vehicle moves forward or backward.

Switching between forward and reverse of a normal automobile is done by manually operating the change lever of the power transmission.
The speed control is performed by depressing the traveling pedal in only one direction in the front direction. However, the prior art traveling pedal device in the wheel type work vehicle is shown in FIGS.
As shown in the figure, the front side a position or the rear side position of the traveling pedal 3'is stepped on to control the speed of the work vehicle to move forward or backward. Such a stepping operation of the traveling pedal 3'is quite uncomfortable for a driver who is accustomed to the stepping operation in only one direction in the front of an ordinary vehicle, and there is a risk of causing a malfunction.

The above-mentioned conventional traveling pedal 3'is, for example, the tenth
As shown in the figure, the maximum depression angle when the front side a position is stepped on is θ′1, and the maximum depression angle when the rear side position is stepped on is θ′2. At that time, the variable hydraulic pump 7 Control lever 9 from the neutral position N'to the a position or the low position.
It is to rotate to the position. However, it is structurally difficult to set the maximum depression angles θ′1 and θ′2 to large angles, and it is difficult to say that the operability of the traveling pedal 3 ′ during the inching depression operation is good. Therefore, it is difficult to drive the work vehicle according to the related art during work that requires inching travel.

Solving the above-mentioned problems of the present invention, it is possible to control the vehicle speed by stepping in only one direction in the front like a normal automobile,
It is an object of the present invention to provide a traveling pedal device that increases the maximum stepping angle at that time to improve traveling drivability.

Means for Solving the Problems The means of the present invention taken to solve the above-mentioned problems are a. Configured so that the traveling pedal can be operated only in one direction in the front direction. The traveling pedal and the control lever of the variable hydraulic pump are connected via a lever bracket assembly and an interlocking link assembly, and c. The lever bracket assembly is fixedly provided with a clutch with both side claws at the center of the detent shaft, and left and right claw links are rotatably fitted to the left and right outer sides of the clutch with both side claws, respectively. Also, fit a spline link to the sprite part of the detent shaft, and The left and right pawl links and the interlocking links are rotatably connected by the left and right connecting rods respectively. By switching a switching lever provided at one end of the detent shaft, the clutch with both side claws is engaged with either one of the left and right claw links.

Work a. Since the traveling pedal can be depressed in only one direction forward, the operating rod connected to the spline link of the lever bracket assembly pushes only in one direction from the neutral position, for example, backward.

B. When the switching lever is switched to the forward position, the detent shaft slides in one direction of the shaft center, and at the same time, the one claw on both sides of the clutch with claws fixed to the detent shaft engages with the claw link on that side, and the other side. The claw link on the side is free.

C. When the switching lever is switched to the forward position and the traveling pedal is depressed, the operation amount pushes the operating rod backward, for example, and the spline link, left claw link, left connecting rod, interlocking link, control rod After that, the control lever of the variable hydraulic pump is rotated in the pushing direction.

D. When the switching lever is switched to the rear position, the detent shaft slides in the direction opposite to the above, and at the same time, the right side claw of the clutch with both side claws fixed to the detent chat engages the link with the right claw and the link with the left claw is free. Becomes

E. When the switching lever is switched to the reverse position and the traveling pedal is stepped on, the stepping amount pushes the operating rod backward, for example, and operates the spline link, right claw link, right connecting rod, interlocking link, and control rod. After that, the control lever of the variable hydraulic pump is rotated in the pulling direction.

Example Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a side view of the overall configuration of the present invention, and FIG.
FIG. 3 is an enlarged detailed side view of the traveling pedal switching device 27 shown in FIG.
FIG. 4 and FIG. 4 are cross-sectional views showing the detailed structure of the lever bracket assembly 10 in FIG. 2, and FIGS. 5 and 6 show the lever bracket assembly 10 and the interlocking link assembly 11 in FIG. It is a plan view showing a combination configuration,
Of these, FIGS. 3 to 6 also serve as explanatory views showing their operating states.

In these figures, 1 is a driver's seat mounted on a floor plate for mounting a driver's cab (not shown) or the like, or a support plate 2 which is a similar member, and 3 is a variable hydraulic pump for generating pressure oil for driving the traveling motor 8. 7 is a traveling pedal for the purpose of controlling the control lever 9 for adjusting the amount of oil discharged, and is normally returned to the open position N by means such as a return spring (not shown). The maximum depression angle θ0 is possible only unilaterally to the front while the vehicle is in the seat 1. 4 has a traveling pedal 3 at one end
Of a rod crank which is pin-jointed to a predetermined position of the rod, and which is interlocked in proportion to the stepping amount, 6 is a bell crank connected to the other end of the rod 4 for converting an operation direction into a desired direction, 5 is a rotation amount of the bell crank 6. Is a rod for transmitting the rotation amount of the spline link 16 on the lever bracket assembly 10 which will be described later. In the embodiment of FIG. 1, the rods 4 and 5 are both compression members when the traveling pedal 3 is depressed. However, the present invention is not necessarily limited to this, and other means such as changing the assembling direction to form a tension member or a flexible wire may be used. Of course there is. The point is that the rotation amount of the traveling pedal 3 may be transmitted to the lever bracket assembly 10 side in accordance with the depression amount of the traveling pedal 3.

Reference numeral 27 denotes a traveling pedal switching device according to the present invention, which is a lever bracket assembly 1 to which one end of the rod 5 is connected.
0, an interlocking link assembly 11 whose operating side that outputs a rotation amount is connected to one end of a control rod 21 for operating the control lever 9, and the interlocking link assembly 11 and the lever bracket assembly 10 with each other. To the left connecting rod 18 and the right connecting rod 19 whose effective length is adjustable.
It consists of

The lever bracket assembly 10 includes a bracket 31 fixed to a standing plate 32 fixed on the support plate 2 with bolts 33, and fixed to the bracket 31. Both ends of the detent shaft 12 are axially connected to each other. A bearing member that freely rotatably and slidably supports and a pivot pin 34 on the erected plate 32 are pivotally supported so as to be swingable. Is provided with a grip, and the other end is connected to the end of the detent shaft 12 via a pin 35,
The detent shaft 1 is operated by operating the grip portion.
The operation lever is composed of a switching lever 20 that allows the slider 2 to slide in the axial direction. In addition, the above detent shaft 12
Has two grooves formed in a portion penetrating one of the bearing members, and a steel ball 3 urged by a spring into one of the grooves.
The structure is such that when 6 is engaged, a detent action is exerted. Further, the spline link 16, the left claw link 14, and the both side claws which are held by both bearing members that axially support both ends of the detent shaft 12 and have a cylindrical main body so as to be inserted into the outer circumference of the detent shaft. With clutch 1
3, the link 15 with the right claw is assembled in this order,
An inner diameter portion of the spline link 16 forms a spline boss, engages with a spline provided at a corresponding position of the detent shaft 12, and the spline length of the detent shaft 12 slides in the axial direction. 1
6 has a size that can hold its position.
A boss portion 29 is fixedly provided on the outer periphery of the spline link 16 in the radial direction thereof, and a pin hole for connecting one end of the rod 5 is formed at a tip end portion of the boss portion 29. . Both the left claw link 14 and the right claw link 15 are rotatably fitted in the outer circumference of the detent shaft 12 with their inner diameters. Claws are provided, and the left and right claw links 1
The detent shaft 12 is fitted in the middle of 4, 15,
The detent shaft 1 by means such as a spring pin
A ring-shaped both-sided claw clutch 13 having a jaw clutch type claw that is fixed to No. 2 and engages with the above-mentioned claw-shaped link is provided. Spacers are inserted so as to keep the distance between the left and right claw links 14 and 15 constant, and the left and right claw portions of the both-side claw clutch 13 and the left claw link 14 and the right claw link 15 are described. It is dimensioned to maintain a space so that it will not engage with the claws of the. That is, by properly setting the width of the spacer, the claws of the clutch 13 with the both-sided claws are at the left and right claw links 14 at one detent position determined by the two grooves provided on the detent shaft 12. , 15 is engaged with one of the claws, and at the other detent position, the claw link on the opposite side is engaged with the claw.

Further, on the outer peripheral portion of the link 14 with the left claw, a boss portion 39 having a pin hole for connecting the one end of the left continuous rod 18 to the tip end in the longitudinal direction is provided. The outer peripheral portion is fixedly provided with boss portions 40 each having a longitudinal direction aligned with the radial direction and a pin hole provided at a tip portion for connecting one end of the right continuous rod 19 to each other. When assembling 15 to the detent shaft 12, when these are rotated in the same direction, the tips of the bosses 39 and 40 are connected to the left and right connecting rods 18,
One of 19 operates in the compression direction and the other in the pulling direction, so that they are generally in the opposite positions,
For example, the left and right connecting rods 18 and 19 are adjusted so that the angle θ3 shown in FIG. 2 is close to 180 °, and the connecting rod assembly 11 described later is connected.

Next, the interlocking link assembly 11 has a tubular interlocking link 17 rotatably supported by a shaft member held at both ends by brackets fixedly mounted on the support plate 2, and a radial direction of the outer periphery thereof. Bosses 30, 37 fixed so that their longitudinal directions coincide with each other,
One end of the control rod 21 is pin-joined to the tip portion of the boss portion 30, and the fixed position of the control rod 21 is proportional to the angle at which the interlocking link 17 rotates to the left and right as much as possible. It is provided so as to rotate and at a position and in a direction in which the left and right connecting rods 18, 19 and the boss portions 37, 38 do not interfere with each other by the rotation. Further, the left end of the left connecting rod 18 and the right end of the right connecting rod 19 are separately pin-joined to the tip ends of the bosses 37 and 38, respectively. When either one of the left and right connecting rods 18 and 19 is operated in the compression direction or the tension direction, the tips of the bosses 37 and 38 are operated in the same direction, that is, Both the boss portions 37 and 38 are fixed to the center line so as to be located on the upper side or the lower side (the upper side in the drawings of the embodiment).

In FIG. 1, 28 is a prime mover for driving the variable hydraulic pump 7 and other devices, 9 is a control lever for the variable hydraulic pump 7 described above, and when the travel pedal 3 is in the open position, N'in the figure shows. Although in the neutral position, the travel pedal 3 is depressed, and the amount of depression acts on the control lever 9 via the travel pedal switching device of the present invention.
Alternatively, when it rotates in the (f) direction, pressure oil and pressure oil amount in the forward and reverse directions are supplied from the variable hydraulic pump 7 to the traveling motor 8 according to the rotation direction and the rotation amount, and the motor 8 rotates in the forward and reverse directions. And rotation speed control.

The operation of the embodiment of the present invention having the above configuration will be described with reference to the drawings.

3 and 4 are views as seen from AA in FIG. 2, but the switching lever 20 is a detailed view when the switching lever 20 is switched to the forward drive position F in FIG. 3 and to the reverse drive position R in FIG. Is. As shown in FIG. 3, when the switching lever 20 is switched to the forward drive position F, the left side claw portion of the clutch 13 with both side claws fixed to the detent shaft 12 meshes with the claw portion of the left claw link 14, but the right claw link. 15 is free, and as shown in FIG.
Is switched to the reverse position R, the right side claw portion of the clutch 13 with both side claws fixed to the detent shaft 12 meshes with the claw portion of the right claw link 15, but the left claw link 14 becomes free.

FIG. 5 and FIG. 6 are the views seen from BB in FIG. 2. When the switching lever 20 is switched to the forward drive position F as shown in FIG. 5, when the traveling pedal 3 is depressed, In conjunction with this, the rod 5 is moved rearward, and its operation amount is determined by the spline link 16, the spline portion of the detent shaft 12 engaged with the spline hole of the spline link 16, and the clutch with both side surface claws fixed to the detent shaft 12. The control rod 21 is pushed rearward through the boss portions 37 and 30 of the left link 13, the link 14 with the left claw, the left connecting rod 18, and the interlocking link 17. Further, when the switching lever 20 is switched to the reverse position R as shown in FIG. 6, the operation amount for pushing the rod 5 backward according to the above is fixed to the spline link 16, the detent shaft 12, and the detain shaft 12. It is transmitted to both side claw clutch 13 and right claw link 15. Here, as shown in FIG. 2, the assembling angle θ3 formed by the boss portion 40 of the right claw link 15 and the boss portion 39 of the left claw link 14 is close to 180 ° as described above, and is about the rotation center. Since the upper and lower parts are arranged separately, the boss portion 40 of the link 15 with the right claw pulls the connecting rod 19 forward to operate,
The operation amount of pulling the connecting rod 19 forward is controlled by the control rod 2 via the boss portions 38 and 30 of the interlocking link 17.
1 is pulled forward and actuated.

7 and 8 show a switching device 27 for a traveling pedal according to the present invention.
FIG. 3 is a side view showing the overall configuration and operation of control of the variable hydraulic pump 7, but when the travel pedal 3 is stepped forward at the maximum stepping angle θ0 and the rod 5 is pushed and operated, the transmission path of the stepped amount is set to the driver's seat. When viewed from 1, the pushing operation to the rear is represented by an arrow →, and the pulling operation toward the front is also represented by ← −. FIG. 7 shows the case where the switching lever 20 is switched to the forward drive position F and the traveling pedal 3 is stepped forward. In the figure, the pushing force of the rod 5 pushes the left claw link 14 and the left connecting rod 18 of the lever bracket assembly 10 backward,
By rotating the control lever 9 of the variable hydraulic pump 7 from the neutral position N ′ to the (e) position via the interlocking link 17 and the control rod 21, the traveling motor 8 is moved forward by the pressure oil discharged from the pump 7. Rotate to. 8th
The figure shows that the switching lever 20 is switched to the reverse position R and the traveling pedal 3 is moved.
This is the case when stepping forward. In the drawing, the pushing amount of the rod 5 pulls the right claw link 15 and the right connecting rod 19 of the lever bracket assembly 10 forward, and the control lever of the variable hydraulic pump 7 is operated via the interlocking link 17 and the control rod 21. Contrary to the above, 9 is rotated in the (f) position direction so that the discharge direction of the pressure oil discharged from the pump 7 is reversed and the traveling motor 8 is rotated in the reverse direction. Next, as another embodiment of the present invention, an embodiment in which the traveling pedal switching device is provided with a neutral position for improving safety will be described. That is, FIG. 9 is a front view showing a partial cross section of the lever bracket assembly 10 ′, but the detent shaft 1
2'is provided with three grooves (g), (h), and (d) as detents that engage with the positioning steel balls 36 '. Therefore, when the switching lever is positioned at the neutral position N, the groove (g) portion of the detent shaft 12 'has the steel ball 3
6'position, in this position the detent shaft 1
The two-sided claw clutch 13 fixed to 2'is not engaged with either of the left and right claw links 14 and 15. Therefore, if the switching lever 20 is set to the neutral position N, even if the traveling pedal 3 of the work vehicle is accidentally depressed, the vehicle does not move forward or backward. The operation when the switching lever 20 is switched to the forward drive position F or the reverse drive position R to depress the traveling pedal 3 is the same as that described with reference to FIGS. 3 and 4.

As described above, in the traveling pedal switching device of the present invention,
By connecting the lever bracket assembly having the reverse lever for switching to the reverse and the clutch with the both side claws and the interlocking link assembly with the left and right connecting rods, respectively, the above-mentioned switching lever selectively presses the traveling pedal in one direction. The quantity transmission direction is switched. That is, simply by depressing the traveling pedal forward, the push lever is operated in the path on the left connecting rod side when the switching lever is at the forward position, and the path is on the right connecting rod side when the switching lever is at the reverse position. By pulling, the variable hydraulic pump and control lever can be controlled from the neutral position to the rear or front position. Therefore, a driver who is accustomed to controlling the speed of the vehicle by only stepping forward in one direction as in a normal automobile can easily drive the vehicle without feeling any discomfort. Further, in the conventional technology method in which the forward and backward operations must be performed with the forward and backward depression angles of the traveling pedal within a limited operating angle range, the forward depression operation angle and the backward depression operation are performed. Since the angles were small, it was difficult for the driver to perform fine control during inching operation.
Inching running performance of the work vehicle was poor. However, in the present invention, the traveling pedal switching device is provided near the driver's seat, the switching lever is switched to the forward position or the reverse position, and the traveling pedal is operated to depress at a large angle in only one forward direction.
Therefore, the feeling of stepping operation is similar to that of an automobile, and the stepping operation angle can be set to be large, so that the minute control at the time of inching stepping operation becomes easy, and the inching traveling operability and safety are improved.

[Brief description of drawings]

FIG. 1 is a side view of the entire configuration of the present invention, FIG. 2 is a side view of the switching device of the present invention, FIGS. 3 and 4 are front views seen from AA in FIG. 2, FIG. 5 and FIG. FIG. 7 is a plan view seen from the line BB in FIG. 2, FIGS. 7 and 8 are side views of the overall configuration of the present invention, and FIG. 9 is another embodiment of the present invention, FIG. 10 and FIG. FIG. 1 is a side view of the overall configuration of a conventional technique. 3, 3 '... traveling pedal 10, 10' ... lever bracket assembly 11 ... interlocking link assembly 12, 12 '... detent shaft 13 ... both side claw clutch 14 ... left claw link 15 ... … Link with right claw 16 …… Spline link 17 …… Interlocking link 20 …… Switching lever

Claims (1)

[Claims] 1. A travel pedal switching device for operating a travel motor with discharge pressure oil of a variable hydraulic pump which is controlled via a rod when a foot-operated travel pedal provided near a driver's seat is depressed. The amount of depression of the traveling pedal (3) of the type that is operated by pushing the rod into the variable hydraulic pump via the rod (5), lever bracket assembly (10), interlocking link assembly (11), and control rod (21). The lever bracket assembly (10) is slidably and rotatably supported at both ends thereof, and has a spline portion near one end thereof.
On the other hand, a detent shaft (12) provided with a detent means capable of holding a plurality of sliding positions, a clutch (13) with both side surface pawls fixedly provided at the center thereof, and left and right of the clutch (13). The detent shafts (12) on both sides are rotatably fitted into each other and selected by the detent means, so that either one of the clutches (13) has a claw on both sides.
Left and right pawl links (14) and (15) that engage with each other, and a spline link (16) that engages with the spline portion and rotates by the operation of the rod (5). ) Is an interlocking link (17) in which a boss portion for actuating the control rod (21) on the outer circumference and boss portions (37), (38) arranged on substantially the same side of the outer circumference are fixed and pivotally supported. ), The left and right connecting rods (18) for rotatably connecting the left and right pawl links (14), (15) and the boss portions (37), (38) on the interlocking link (17), respectively. , (19), when the left and right claw links (14), (15) rotate in the same direction,
A switching device for a traveling pedal of a wheel type working vehicle, characterized in that one of the left and right connecting rods (18), (19) is assembled so that a compression member and the other become a tension member.