JP2002161555A - Operation lever device of construction machine or the like - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation lever device having an operational position retaining mechanism which reduces the frictional force between the ball of the position retaining mechanism and rolling face so that the operational lever is automatically made returnable securely to the neutral position. SOLUTION: In an operation lever device 18 of a construction machine constituted so as to be retained at the operational position by the position retaining mechanism 19, notches 25, 26 are provided respectively at the retaining position before and behind the operational lever 15, on the ball rolling face of the operation position retaining mechanism. The central part of the ball-rolling face between both notches 25, 26 is formed as the central position of the operational lever 15, and a gentle slope face is formed from the notch end before and behind the operation lever toward the neutral position 29. The operational lever device of the construction machine in which the friction force between the ball 27 and the ball rolling face is reduced on the gentle slope face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating lever device for a construction machine or the like, and in particular, requires an operating force in a neutral direction only when releasing the holding of the operating lever in front and rear holding positions. The present invention relates to an operation lever device of a construction machine or the like formed such that the operation lever is automatically returned to a neutral holding position and held.

[0002]

BACKGROUND OF THE INVENTION Problems to be Solved by the Invention
A pile driver provided with such an operation lever device will be described with reference to FIG. In the drawing, reference numeral 1 denotes a pile driver. In the pile driving machine 1, an upper swing body 3 is rotatably mounted on a lower traveling body 2, and a boom 4 is mounted on the upper swing body 3 such that the boom 4 can be raised and lowered by expansion and contraction of a boom lifting cylinder 5. or,
A kelly bar hanging rope 7 is drawn out from a winch 6 provided on the upper swing body 3 and wrapped around the top of the boom 4. A rotary drive device 10 for rotating and driving the kelly bar 8 and a digging bucket 9 attached to the lower end of the kelly bar 8 is suspended from the boom 4 by a support rope 11. Further, the rotary drive device 10 is supported at a lower portion of a support frame 12, and the support frame 12 is pivotally attached to a front portion of the upper rotating body 3 by an up-and-down cylinder 13 so as to be able to move up and down.

The operating lever 15 of each of the above-mentioned hydraulic devices is
Is provided in the cabin 14, and the operation of the operation lever 15 is transmitted to the hydraulic control valve 17 through the connection link 16,
Each hydraulic device is configured to operate when pressure oil is supplied to or removed from the hydraulic device via the hydraulic control valve 17.

Therefore, a conventional operation lever device 18 of this type will be described with reference to FIGS. In the figure, the operation lever device 18 includes an operation lever 15 and an operation position holding mechanism 1.
9 Thus, the operating lever 15 is
4, and a base end thereof is pivotally supported by a concave portion 20 a provided in the operation table 20, and projections 22, 22 are provided before and after an upper portion of a pivot point 21 of the operation lever 15,
Further, push seats 23a, 23a pressed by neutral return springs 23, 23 are provided on the respective front end surfaces of the projections 22, 22, respectively.
Is in pressure contact. That is, the neutral direction return springs 23, 23
Presses the protrusions 22 and 22 at all times to
To return to the neutral position. The neutral direction return springs 23, 23 are respectively provided with screws 23b,
The front and rear biasing force can be adjusted at 23b.

One end of a lever 24 extending in one direction is pivotally connected to an intermediate portion of the operation lever 15.
Further, an inverted triangular rear notch 26 corresponding to the front holding position of the operation lever 15 and an inverted triangular front notch 25 corresponding to the rear holding position are provided on the front and rear surfaces of the lever 24. And the front notch 25 and the rear notch 2
6 is formed on a horizontal turning surface 28 of the ball 27, and the center position of the turning surface 28 is a neutral position 29 of the operation lever 15. That is, the neutral position 29 is a point where the urging forces of the front and rear neutral return springs 23 are balanced.

Further, the ball 27 is always urged downward by an upper spring 31 on the lower surface release portion 30a of the holding holder 30 attached to the operation table 20, on the upper surface of the lever 24. And the turning surface 28
The front notch 25 and the rear notch 26
And can be stopped at a neutral position 29 in the center of the turning surface 28 by the bias of the neutral return springs 23, 23. Further, the spring 31 pressing the ball 27 from the upper surface is configured so that the biasing force can be adjusted by a screw 32, and thus the operation position holding mechanism 19 is configured.

Further, the lever 24 is connected to the holding holder 30.
Is formed so as to be slidable left and right between a lower surface of the right side and an upper surface 20b on the right side forming the concave portion 20a formed in the operation console 20. A handle 15a is fixed to the upper end of the operation lever 15, so that the operator operates the operation lever 15 while holding the handle 15a to operate the hydraulic equipment. is there.

Since it is extremely difficult for the conventional operating lever device 18 to allow the operator to simultaneously operate the various hydraulic devices while keeping the operating lever 15 in a fixed position, the operating lever 15 is Operation position holding mechanism 1
9 is configured to be stably held at the front fixed position, the neutral position, and the rear fixed position. However, as shown in the operation torque diagram of FIG. 5, for example, when the operation lever 15 is held at a fixed position on the right side,
The operation lever 15 is gripped and rotated to the right in the drawing, and the ball 27 is fitted into the front notch 25 to hold the operation lever 15 at the rear holding position.

Further, when returning the operating lever 15 held at the rear holding position to the neutral position, the operator grips the operating lever 15 and turns it to the left in the figure. Is returned to the neutral position. However, if the spring force F _Sa of the neutral return spring 23 is weakened in order to improve the operability of the operating lever 15, it is not possible to correctly return to the neutral position due to the mechanical frictional force of the operating position holding mechanism 19 and the like. Occurs. The user turns the operation lever 15 to the left in the figure to move the operation lever 15
The same inconvenience arises when the camera is held in the fixed position on the left side and is returned to the neutral position from the fixed position on the left side.

[0010] That is, it said at the right side next to _{F ia = F Sa -Fμ + F} D ............... 1 Formula _{F Oa = F Sa + Fμ +} F D ............... 2 expression, and, in at the left side F the _{ib = F Sb -Fμ + F D} ............... 3 formula _{F Ob = F Sb + Fμ +} F D ............... 4 expression. A: Rear fixed position B: Front fixed position O: Neutral position F _ia : Actual A direction operation force F _ib : Actual B direction operation force F _Sa and F _Sb : Spring force of neutral direction return spring Fμ: Ball F _D : Notch holding force Actually, in addition to the above-mentioned friction, friction also occurs at a pivot point, a push seat, and the like, but these are omitted for convenience of explanation. FIG. 5 above
As can be understood from the operation torque diagram and the above formula, the portion indicated by the chain line near the neutral position O does not reliably return to the neutral position. In this case, the frictional force between the ball 27 of the operation position holding mechanism 19 and the turning surface 28 thereof acts as an operating resistance, and hinders the operation lever 15 from returning to the neutral position. If so, the operator operates the operation lever 15.
Must be manually returned to the neutral position. If the operator forgets to return the operation lever 15 to the neutral position, the operation lever 15 stops before the neutral position, so that there is a defect that an unexpected accident occurs.

Therefore, there is provided an operation lever device having the operation position holding mechanism, wherein the frictional force between the ball of the operation position holding mechanism and the turning surface is reduced so that the operation lever can be automatically returned to the neutral position without fail. Therefore, a technical problem to be solved arises, and an object of the present invention is to solve the problem.

[0012]

SUMMARY OF THE INVENTION The present invention has been proposed in order to achieve the above object, and has an operation lever device for a construction machine which is configured to be held at an operation position by an operation position holding mechanism. In the operation position holding mechanism, a notch is provided at each of the front and rear holding positions of the operation lever on the ball turning surface of the operation position holding mechanism, and the center of the ball turning surface between both notches is set as a neutral position of the operation lever. And an operation lever device for a construction machine in which a gentle slope is provided from the front and rear notch ends toward the neutral position, and the frictional force between the ball and the ball turning surface is reduced by the gentle slope. To provide.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. The same components as those of the conventional example are denoted by the same reference numerals, and a part of the description is omitted.

In FIG. 1, one end is pivotally attached to an operation lever 15 and the upper surface of a lever 24 that slides left and right with the left and right rotation operation of the operation lever 15 is provided on the upper surface as in the conventional example. A rear notch 26 corresponding to the front holding position of the operation lever 15 and a front notch 25 corresponding to the rear holding position are provided, and the operation lever 15 is in both of these holding positions even when the hand is released. It is configured to be stably held.

In the present invention, as shown in FIG. 1, the ball 2 is located between the front notch 25 and the rear notch 26.
The turning surface 7 is formed in a concave portion 33 having a gentle curved surface. That is, the concave portion 33 is formed so that the center portion 33a is formed deepest, and a gentle slope is provided toward the notch edges of the left and right front notches 25 and the rear notch 26 in FIG. The portion 33 is formed. Accordingly, when the ball 27 of the operation position holding mechanism 19 is released from the engagement with the front notch 25 or the rear notch 26 and the operation lever 15 is returned to the neutral position, the inclination of the concave portion 33 where the ball 27 turns is adjusted. The frictional force between the surface and the ball 27 is significantly reduced, so that the holding of the ball 27 is released from the rear notch 26 corresponding to the front holding position of the operating lever 15 or the front notch 25 corresponding to the rear holding position. Then, the neutral position, that is, the center position 33 of the concave portion 33
When returning to a, the ball 27 smoothly rolls on the upper surface of the concave portion 33 only by releasing the front or rear holding position by applying an operating force to the operating lever 15 in the neutral direction. However, it is possible to easily return to the center position of the concave portion 33, that is, the neutral position by the bias of the neutral direction return spring 23.

As described above, since the operation lever 15 does not stop short of the center position 33a, the operator manually returns the operation lever 15 stopped short of the neutral position to the neutral position as in the related art. No longer needed
Therefore, occurrence of an accident due to the operator forgetting to return can be prevented beforehand.

That is, as shown in the operation torque diagram of FIG. 6, the frictional force Fμ between the ball 27 and the concave portion 33 is reduced, and the actual return force by the neutral return spring 23 is obtained. F _Oa or F _Ob acts to the neutral position O, and the operation lever 15 surely returns to the neutral position O and stops. As described above, if the operation force for returning the operation lever 15 to the neutral position O is applied when the front notch 25 or the rear notch 26 is released, the operation lever 15 can be neutralized even if the hand is released from the operation lever 15 halfway. It will automatically return to its position.

Next, another embodiment of the present invention will be described with reference to FIG. In the figure, an operation position holding mechanism 34 is attached to an open portion on the lower surface of the operation console 20 with bolts 35, 35,. Thus, the operating position holding mechanism 34 has front and rear (left and right in FIG. 2) opening holes 36,
36 are provided.
Sliding pieces 38, 38 urged upward at 7, 37 are provided movably up and down, and are further pressed upward by a spring 39 at the center between the sliding pieces 38, 38. Push seat 4
At 0, the ball 41 is urged upward.

The operation lever 42 moves forward and backward at the lower portion (FIG. 2).
In the left and right directions) to form a substantially trapezoidal shape.
38, and the sliding pieces 38, 38 urge the lower surfaces of the protruding portions 43, 43 evenly upward, thereby assisting the operation lever 42 to move forward and backward properly. ing.

Further, a front notch 44 and a rear notch 45, each of which is cut in a triangular shape, are provided before and after (in FIG. 2, right and left) a center portion between the overhang portions 43, 43 as a neutral position. Have been. Therefore, the ball 41 is configured such that the operating position of the operating lever 42 is held at both the front notch 44 and the rear notch 45, and the ball 41 can return to the neutral position at the center. Therefore, the rolling surface of the ball 41 at the neutral position portion is formed as a substantially triangular concave surface or a flat surface 46 having a gentle slope in front and rear with respect to the pressing force of the ball 42 with the neutral position as the apex. ing. Accordingly, the frictional force Fμ between the ball 41 rolling on the concave surface or the flat surface 46 and the concave surface or the flat surface 46 is significantly reduced, and the operation of the operation lever 15 shown in FIG. be able to.

The operating lever 42 is provided with the overhanging portion 43,
At the front and rear (left and right in FIG. 2) of the upper part of 43, a protrusion 47,
47, and projecting portions 47, 47 are returned to neutral return spring 4.
The operating lever 42 is constantly and evenly urged from the front and rear so that the operating lever 42 returns to the neutral position.

The operating lever 42 is connected to the overhang 43,
A central portion of the upper portion of 43 is pivotally supported on a shaft 49 so that the shaft can be moved back and forth with the shaft 49 as a pivot point. The rest of the configuration is exactly the same as the operation lever device shown in FIG. 1, and each of the operation lever devices shown in FIGS. 1 and 2 performs exactly the same operation.

Although the embodiment of the present invention has been described with respect to a construction machine, the invention is not limited to the construction machine but may be applied to agricultural machines, vehicles, cranes and the like.

Further, in the embodiment of the present invention,
Although the output of the operation lever is mechanically derived, a device that converts it into an electric signal, hydraulic pressure, pneumatic pressure, water pressure, etc. is installed inside the operation lever device, and the operation lever automatically moves to the neutral position through such devices. The return may be performed.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0026]

According to the present invention, as described in detail in the above embodiment, when the operating lever is returned from the front holding position or the rear holding position to the neutral position, the holding lever is simply released from the holding position. The operation lever can be automatically and reliably returned to the neutral position except for the holding position even if the hand is released halfway by only the manual operation force. That is, since the concave portion or the concave surface, which is also the ball and ball rolling surface of the operation position holding mechanism, is formed with a very gentle slope, the frictional force between the ball and the ball rolling surface is significantly reduced. This makes it possible for the operation lever to automatically return to the neutral position with certainty. Therefore, it is not necessary to increase the spring force of the neutral direction return spring, and the operability of the operation lever is improved.

Further, unlike the related art, the operation lever does not stop just before the neutral position, so that the operator does not forget to return, so that a serious accident caused by forgetting to return can be prevented. It is an invention that has a truly significant effect.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an operation lever device of the present invention.

FIG. 2 is a longitudinal sectional side view of an operation lever device showing another embodiment of the present invention.

FIG. 3 is a side view of a pile driver equipped with the present invention and a conventional operation lever device.

FIG. 4 is a longitudinal side view of a conventional operation lever device.

FIG. 5 is an operation torque diagram of a conventional example.

FIG. 6 is an operation torque diagram of the present invention.

[Explanation of symbols]

 15, 42 Operating lever 18 Operating lever device 19, 34 Operating position holding mechanism 23, 48 Neutral return spring 24 Lever 25, 44 Front notch 26, 45 Rear notch 27, 41 Ball 29 Neutral position 33 Concave portion 46 Concave or flat surface

Claims (1)

[Claims] 1. An operation lever device for a construction machine configured to be held in an operation position by an operation position holding mechanism, wherein the ball turning surface of the operation position holding mechanism holds the operation lever back and forth. A notch is provided at each position, the center of the ball turning surface between both notches is set to the neutral position of the operation lever, and a gentle slope is provided from the front and rear notch ends toward the neutral position. And a frictional force between the ball and the ball turning surface is reduced by the gentle slope.