JPH0534428Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a link device that can simultaneously control drum rotation and engine control of a concrete mixer truck.

[Prior Art] Generally, the rotational direction of the drum of a concrete mixer truck is controlled by switching the discharge direction of high-pressure oil from a hydraulic pump.

Further, the rotational speed of the drum is controlled by controlling the flow rate of high-pressure oil by increasing or decreasing the rotational speed of a hydraulic pump by controlling the flow rate of high-pressure oil and the engine rotation of the vehicle.

For these controls, the engine-side mechanism and the hydraulic pump-side mechanism are connected to a control lever installed in the driver's seat of the concrete mixer vehicle by rods or cables, respectively, and the hydraulic pump is controlled by operating the control lever in the left and right directions. The engine is controlled by vertical operation.

The conventional operating device described above has two systems: a control system for the flow rate and discharge direction of the hydraulic pump, and a control system for the engine, so the control system has a large number of operating parts.
It is complex and less economical. Furthermore, there are two operating directions of the operating lever, ie, left-right direction and up-down direction, which may lead to operational errors.

Therefore, an electrically controlled operating device for a concrete mixer vehicle has been developed that allows the hydraulic pump and engine to be controlled by operating in the same direction.

However, with the above-mentioned electrically controlled operating device, even if the operator operates the controller, the controller may move erroneously or not operate due to some electrical trouble. In this case, it is necessary for the operator to return the rotation of the drum to neutral, but this operation is extremely troublesome, or there are cases where the ready-mixed concrete is poured due to failure to take appropriate measures.

Therefore, the applicant has developed a link device for a concrete mixer truck that can control the drum arbitrarily and safely operate even in abnormal situations such as electrical system troubles (Utility Model Application No. 45581/1983). 1
−148941)).

In this link device, the main link is rotatably supported on a central fixed shaft, and the ends of a forked link for engine control, which is made up of two links, are rotatably supported on this shaft. First and second bosses are provided facing each link of the forked link, and an arm is provided below the main link. One end of the arm is rotatably supported below the central axis of the main link. A receiving portion opening upward is provided at the end, a main link is removably fitted into the receiving portion, and a driving link on the servo motor side is connected to the arm. a groove rotatably engaged with a link for controlling the hydraulic pump, the link for controlling the hydraulic pump having a groove at an end into which a second boss is rotatably fitted;
This groove is characterized by having two tapered surfaces that expand in diameter from this groove.

Then, if the main link is removed from the receiving part via the manual operation handle provided on the main link and operated, the main link is disconnected from the drive link and servo motor and can be operated manually regardless of electrical system trouble. A link for hydraulic pump control and a bifurcated link for engine control are controlled.

[Problems to be solved by the invention] However, the above link device has the following problems.

If you operate the main link with the manual operation handle while the main link is connected to the servo motor side via the receiving part and the drive link, the servo motor will be in a locked state, so the force of the main link will also be transferred to the servo motor side. There is a risk that the load will be transmitted and an excessive load will be applied to the servo motor.

When controlling a vehicle's engine, if the electric signal from the controller is used to operate the servo motor and the drive link beyond the stroke of the vehicle's cabana, the engine will become locked and an excessive load will be placed on the servo motor. There is a risk that it will become stiff.

Similarly, if the hydraulic pump side becomes locked, or if a mechanical system such as a ring device gets jammed and becomes locked, an excessive load will be generated on the servo motor.

As described above, if an excessive load is applied to the motor, internal mechanisms such as gears inside the servo motor will be damaged.

Therefore, an object of the present invention is to provide a link device that does not apply an excessive load to the servo motor even if some mechanism is locked or malfunctions.

[Means for solving the problem] In order to achieve the above purpose, the configuration of the present invention is as follows.
The center of the main link is rotatably supported on the bracket of the support base via a shaft, an engine control link is supported at the center of the main link via the shaft, and an arm is provided below the main link. One end of this arm is supported by the shaft, the main link is detachably connected to the other end of the arm, one end of a drive link is connected to the arm via a bracket, and one end of the main link is connected to the arm. In a link device in which a hydraulic pump control link is connected, a manual operation handle is connected to the other end of the main link, and the other end of the drive link is connected to the output shaft of a servo motor, the drive The link consists of an outer tube and an inner rod that is movably inserted into the outer tube. A positioning ball that is biased inward is provided inside the outer tube, and a positioning ball is removably engaged with the outer circumference of the inner rod. It is characterized by forming a recessed portion.

[Function] If excessive force is applied to the main link side, the outer tube will move in the direction of extension or compression, and the positioning ball will come off the recess of the inner rod.
The movement of the outer tube is not transmitted to the inner rod, and as a result, no excessive load is applied to the servo motor.

[Example] Hereinafter, an example of the present invention will be described based on the accompanying drawings.

The concrete mixer truck is as shown in Figure 3.
It has a hydraulic pump 2 or a hydraulic servo that controls the rotational direction and speed of the engine 1 and the drum, and the engine 1 and hydraulic pump 2.

The link device 4 includes a main link 8 whose center is rotatably supported via a shaft 7 on a bracket 6 of a support base 5, and two main links whose center is rotatably supported via a shaft 7. A bifurcated link 11 for engine control consisting of links 9 and 10, a control rod 13 which is a drive link connected to one side of the main link 8, and a control rod 13.
An arm 14 whose other end is connected to the output shaft of the servo motor 3, and a cam member 15 on the other side of the main link 8.
The hydraulic pump control link 16 is rotatably engaged through the hydraulic pump control link 16.

The main link 8 has first and second bosses 1 on both sides.
7 and 18 are provided, and the bosses 17 and 18 stand upward and face the links 9 and 10.

An arm 31 is provided below the main link 8. One end of the arm 31 is rotatably supported below the shaft 7. A receiving portion 32 that opens upward is provided at the end of the arm 31. The main link 8 is removably fitted and coupled to the main link 8.

One end of the control rod 13 is connected to the arm 31 via a bracket 33.
As shown in FIG. 7, the receiving part 32 is composed of a leaf spring 33 with a narrow opening formed by drawing the upper part inward, and the main link 8 is held within the leaf spring 33, but the spring force When the main link 8 is pushed upward against the force, the main link 8 is removed upward.

Further, the main link 8 is provided with a pair of support pieces 34 that open downward, and the arm 31 is fitted between the support pieces 34 . Therefore, the main link 8 and the arm 31 are stacked vertically, and the receiving part 3
The main link 8 and the arm 31 are connected via the support piece 34 and the main link 8, and when the main link 8 is pushed upward, the main link 8 and the arm 31 are separated.

When the two are connected, they move as one,
When the main link 8 is manually pulled up via the handle 35 at the end, the main link 8 is independently rotated.

When the output shaft of the servo motor 3 rotates, the rotational motion is transmitted to the main link 8 via the arm 14, control rod 13, and arm 31, and the main link 8 rotates clockwise or counterclockwise around the shaft 7. Rotate.

Each link 9, 10 of the forked link 11 is connected to an intermediate rod 9a, 10a, and
The other end of the arm 28 is pivotally connected to the head 28a of the arm 28, which is pivotally connected to the bracket 27 of the support base 5, and the lower part of the arm 28 is connected to the engine 1 via an accelerator operation link 29.

One of the links 9 and 10 is pressed, and the intermediate rod 9
When one of the arms a and 10a is pushed out, the arm 28 rotates counterclockwise in the table 3 using the shaft 39 as a fulcrum, and the link 29 is pulled and displaced from the idling position a to the high speed position b.

The link 16 for controlling the hydraulic pump is the cam member 15
and an L-shaped link 20 connected to the cam member 15,
21, and a tilting angle control link 22 connected to the link 21. When the link 21 is displaced counterclockwise in FIG. 3, the link 22 is pulled and the hydraulic pump 2 rotates forward. Rotate the drum to the input side,
When displaced counterclockwise, the link 22 is pushed and the hydraulic pump 2 is reversed, rotating the drum toward the discharge side.

The cam member 15 has a plate body, a semicircular groove 23 provided at the end of the plate body, and two tapered surfaces 24 whose diameter expands outward from the groove 23. , the second boss 18 fits into the groove 23 and engages with it, and when the main link 8 rotates clockwise or counterclockwise, the second boss 18 gradually disengages from the groove 23 and hooks on the tapered surface 24. It's starting to become easier.

Next, the operation of the link device will be explained.

The state shown in FIG. 4 shows an intermediate position in which the main link 8 is maintained in a horizontal state and the second boss 18 is fitted into the groove 23. At this time, the drum of the concrete mixer truck and the hydraulic pump 2 are in the middle position X, and the engine 1 is in the idling position a.

When the arm 14 of the servo motor 3 in FIG. 3 is rotated clockwise, the control rod 13 and arm 31 are pushed, and the main link 8 is rotated counterclockwise with the shaft 7 as the fulcrum, as shown in FIG. Rotate it.

At this time, while the second boss 18 is fitted into the groove 23, the cam member 15 is pushed clockwise, the hydraulic pump control link 16 is rotated clockwise, the link 22 is pulled, and the drum is agitated. Controlled in the input direction.

When the link 21 reaches the maximum loading position Y, the second
The boss 18 is removed from the groove 23, and at this time, the first boss 17 comes into contact with one link 9 of the forked link 11 and pushes it in. When the link 9 of the forked link 11 is pushed, the intermediate link 9a is pushed, the entire forked link 11 is extended, and the engine 1 changes from the idling position a to the high speed position b.

When the engine rotates at high speed, the first boss 17 pushes the bifurcated link 11 to the maximum, and at this time the second boss 18 comes off the groove 23 and is only supported by the tapered surface 24, leaving the link 16 for hydraulic pump control. does not change and is held at the maximum input position Y.

Contrary to the above, when the control rod 13 is pulled counterclockwise, the main link 8 rotates counterclockwise, the hydraulic pump control link 16 is pushed counterclockwise, and the drum is set at the discharge position Z. be done.

At this time, the second boss 18 pushes the other link 10 of the forked link 11, causing the engine 1 to rotate at high speed.

By the way, if the electrical system including the controller 40, servo motor 3, etc. that controls the control rod 13 breaks down or stops working, the following operations are performed manually.

When the main link 8 is pulled upward through the handle 35, the main link 8 resists the spring force of the leaf spring 33 and floats upward from the receiving portion 32 as shown by the dotted line in FIG. Move away from arm 31.

For this reason, the main link 8 is separated from the arm 31, control rod 13, and servo motor 3.
The main link 8 can be manually rotated clockwise or counterclockwise via the handle 35. The operation of the link mechanism in this case is the same as in the normal case. Therefore, if the electrical system fails, the drum can be controlled arbitrarily by manual operation.

Incidentally, when the control rod 13 is moved in one direction via the servo motor 3 by electrical control,
Depending on the direction of operation, the hydraulic motor and the drum are controlled in the agitation, input or discharge direction, and at the same time the engine is controlled. Therefore, the control directions of the engine and the hydraulic pump are the same.

Next, the structure and operation of the control rod 13, which is a driving link according to the present invention, will be explained in detail.

Control rod 12 is outer tube 4
0 and an inner rod 41 movably inserted into the outer tube 40. The outer tube 40 is connected to the arm 43 on the main link 8 side via a bracket 42, and the inner rod 41 is connected to the servo motor 3 via a bracket 44. is connected to the arm 14 of. However, the outer tube 40 may be connected to the servo motor 3 side, and the inner rod 41 may be connected to the main link 8 side.

The outer tube 40 is provided with a cylindrical body 45, and a positioning ball 46 is housed in the cylindrical body 45 so as to be vertically movable.
and a spring 47 interposed between the seat 48 and the
constantly urges the positioning ball 46 inward of the outer tube 40.

A recess 49 consisting of an annular groove or the like is formed on the outer periphery of the inner rod 41, and a positioning ball 46 is normally fitted into this recess 49. As a result, the outer tube 40 and the inner rod 41 are connected and the two are interlocked. It moves.

However, either the outer tube 40 or the inner rod 41 is locked, and an external force exerts an expansion/contraction force on either one.
When this force overcomes the spring force of the spring 47, the positioning ball 46 moves into the recess 49 as shown in FIG.
Outer tube 4 is separated from the outer tube and is subjected to external force.
0 or the inner rod 41, only one of them moves. As a result, the outer tube 40 and the inner rod 41 are separated and do not interlock, thereby preventing an excessive load from being applied to the servo motor 3 side.

For example, if the servo motor 3 is stopped and the connection between the control rod 13 and the main link 8 is still intact, the manual operation handle 3
5, the operating force acts as an external force on the outer tube 40 via the main link 8, or the engine 1 or hydraulic pump 2 is locked, or the link device 4 is malfunctioning. When the servo motor 3 is driven at times, an external force from the servo motor 3 side acts on the inner rod 41.

In such a case, an excessive load is usually applied to the servo motor 3 and there is a risk of damage to the servo motor 3, but in the case of the present invention, the outer tube 40 or inner rod 41 on which external force is applied
The servo motor 3 is moved to release the external force, thereby preventing excessive force from acting on the servo motor 3.

[Effect of the idea] According to the present invention, there are the following effects.

When an excessive load is applied to the drive link, the edge between the outer tube and inner rod is severed, and only the side on which the external force is applied can move and release the external force, so that no excessive load is applied to the servo motor. Damage to the servo motor can be prevented.

Since engine control and hydraulic pump control can be performed simultaneously by using one link mechanism, the number of parts in the control mechanism is reduced, the structure is simple, and the ease of assembly is improved.

Since the engine control direction and the hydraulic pump control direction are the same, operation is easy and there is no possibility of operational errors.

Furthermore, if the electrical system breaks down or does not operate, the system can be switched to manual operation and the drum can be controlled, making it safer and preventing ready-mixed concrete from being discharged onto the ground.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an electric control device using the drive link of the present invention, Fig. 2 is a sectional view of the drive link according to an embodiment of the present invention, and Fig. 3 is an enlarged sectional view of Fig. 2. , FIG. 4 is an enlarged plan view of the main link section, FIG. 5 is a front view of FIG. 4, FIG. 6 is a schematic plan view of the main link in a changed state, and FIG. 7 is an enlarged side view of the receiving section. It is. Explanation of symbols, 8... Main link, 9, 10,
11, 16... Link, 13... Control rod, 40... Outer tube, 41... Inner rod, 46... Positioning ball, 49...
recess.

Claims (1)

[Scope of utility model registration request] The center of the main link is rotatably supported on the bracket of the support base via a shaft, an engine control link is supported at the center of the main link via the shaft, and an arm is provided below the main link. One end of the arm is supported by the shaft, and the main link is detachably connected to the other end of the arm,
Further, one end of a drive link is connected to the arm via a bracket, a hydraulic pump control link is connected to one end of the main link, a manual operation handle is connected to the other end of the main link, and the drive link is connected to the arm via a bracket. In a link device whose other end is connected to the output shaft of a servo motor, the drive link consists of an outer tube and an inner rod movably inserted into the outer tube, and an inner rod is inserted into the outer tube. 1. A link device characterized in that a positioning ball is provided with a force applied to the inner rod, and a recess is formed on the outer periphery of the inner rod to removably engage with the positioning ball.