JPH0256247B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an actuating device for an actuator in a construction machine or the like.

When an actuator of a construction machine or the like is operated by pressure oil from a hydraulic pump driven by an engine, the control lever of the oil passage switching valve for switching the pressure oil to the actuator side has an accelerator operation function, It is known in the past that this control lever is configured to perform the switching operation of the oil passage switching valve and the accelerator operation, and that the accelerator is driven after switching the oil passage switching valve with this operating lever (particularly Publication No. 58-38329). However, in this conventional method, the accelerator is driven after the operating lever has been completely switched, so the following problems are involved. In other words, in general, even if the spool of an oil passage switching valve does not completely reach the stroke end (the switching end position of the oil passage switching valve), the center bypass passage leading from the pump to the tank side is closed before the stroke end. Since the oil passage to the actuator side is closed and has the property of being essentially switched, as the oil passage switching valve is switched, the speed of the actuator gradually increases, but at a position in the middle of switching the switching valve, the actuator speed decreases. remains constant until the end of the spool's stroke, after which the accelerator is actuated to increase the speed of the actuator. This characteristic is shown in a graph as shown in FIG. In the figure, A is an area where the speed of the actuator increases due to switching of the spool of the oil passage switching valve, and B1 is an area where the speed of the actuator increases due to driving of the accelerator.
M and N are the maximum flow rates flowing to the actuator in each region. As is clear from this figure,
The speed of the actuator is constant from the spool stroke (4 mm) at which the oil passage switching valve is actually switched to the stroke end (7.5 mm) (area C), which can be seen from the operating sensation of the operating lever. However, the speed control of the actuator was not continuous, making it difficult to use.

Therefore, in the present invention, the accelerator is operated when the oil passage switching valve is substantially switched and the speed of the actuator reaches its maximum, so that the speed of the actuator can be continuously controlled. . Therefore, the accelerator should start operating at the spool stroke of 4 mm, which is the point at which the oil passage switching valve is substantially switched. That is, the operating characteristics in this case are A-B in Figure 2.
This will be line 2. In this case, even if the accelerator starts to operate slightly before or after the spool stroke position of 4 mm, continuity will not be lost in actual sense.
In this case, the operating characteristic of the former is the line A'-B3, and that of the latter is the line A-C'-B4.

In addition, since this conventional operating lever is made of an elastic body made of relatively hard rubber or the like and can be bent, the direction of bending is not constant. There was a problem in that the user had to be careful to operate the device in the same direction as the operating direction. For this reason, the present invention uses an operating lever device in which the switching operation direction of the oil passage switching valve and the accelerator drive operation direction match.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows an overall configuration diagram of a crane 1 which is an example of construction machinery etc. to which the present invention is applied, and 2 is an oil passage switching valve that switches pressure oil from a hydraulic pump (not shown) driven by an engine. This actuates each actuator of the crane (for example, the cylinder 3 for raising and lowering the boom). 4 is an operating lever for switching this oil passage switching valve;
In this example, they are provided on both sides of the crane so that they can be operated from either side of the crane, and are connected by a rod 5.

Although six operating levers 4 are shown in the figure, the bottom two operating levers are conventionally known operating levers that only have the function of simply switching the oil passage switching valve. The operating levers used are the four operating levers above.

FIG. 4 shows an enlarged detailed view of the operating lever mechanism and the accelerator operating mechanism, and FIG. 5 shows an enlarged detailed view of the operating lever and an explanatory diagram of its operation. In the figure, a plurality of oil passage switching valves 2, an operating lever 4, and a rod 5 are shown in order to operate a plurality of actuators, but in the following description, one set of operating mechanisms will be explained.

In FIG. 5, diagram C shows the neutral position of the oil passage switching valve 2. First, to explain the configuration of the operating lever 4, 6 is a spool for switching the oil passage of the oil passage switching valve 2;
Reference numeral 7 denotes a link rotatably supported around a pin 8 at a fixed position, and by rotating left and right around this pin 4, a recess 9 provided at one end of the link and the appropriate position of the spool 6 are connected. The spool 6 is configured to be engaged with a provided pin 10 to switch the spool 6. Reference numeral 11 denotes a lever portion, one end of which is rotatably supported by the pin 8, and a handle 12 is provided at the other end. 13 is
A bush 1 that is slidable on the outer periphery of the lever part 11
4 and a stopper member 15 screwed onto the lever part, so that the bush 14 is pressed against the link 7 by the spring 13,
The lever portion 11 and the link 7 are restrained so that the lever portion 11 swings relative to the link 7 only when a predetermined operating force is applied to the operating lever 4. This restraining force can be adjusted by adjusting the screwing position of the stopper member 15. 1
6 is an operating link attached to one end side of the operating lever 4.

Therefore, when the handle 12 of the operating lever 4 is rotated in the direction of the arrow, the link 7 is rotated together with the lever portion 11.
rotates around the pin 8 and switches the spool 6 of the oil passage switching valve 2 (Figures B and D). Next, when further operating force is applied to the handle 12 from the switching position,
The spool 6 has already reached its stroke end and does not operate, but this time the elastic force of the spring 13 is overcome by the operating force, and the restraint between the lever portion 11 and the link 7 is released, and only the operating lever 4 is pinned. 8 (Figure A or E).

Next, the link mechanism connected to the accelerator drive section will be explained (FIG. 4). A protrusion 17 is fixed at a proper position on the rod 5. On the other hand, on the base side of the crane, there is an L with pins 20 and 21 approximately in the middle.
Two letter-shaped links 18, 19 are pivotally supported on the linkage mounting bracket so as to be rotatable about and together with these pins. One end side 18a, 19a of each of these links is connected to the projection 17.
The rods 5 are disposed at a predetermined distance on both sides of the projection 17 at a predetermined interval, which will be described later, and are in a position where they come into contact with the protrusion 17 when the rod 5 moves left and right by a predetermined distance, which will be described later. A pin 22 is fixed to the other end 19b of the link 19, and the other end 18b of the link 18 is loosely fitted to this pin 22, preventing the link 18 or 19 from rotating around the pin 20 or pin 21. , the other end side 18 of this link 18 or link 19
link 19 or link 18 via b or 19b
This link 19 (or link 18) connects pin 21 or pin 20 around pin 21 or pin 20.
It is configured to rotate together with 0. pin 21
A link 23 is fixedly attached to the link 23, and this link 2
A link 24 is pivotally supported at the other end of the crane 3, and the other end of the link 24 is attached to a rotation link 25 rotatably supported on the base of the crane. This rotation of the rotation link 25 is transmitted to the accelerator drive section 27 of the engine E via the push-pull cable 26. Note that reference numerals 28 and 29 indicate manual accelerator operating levers, and these accelerator operating levers are connected by a rod 32. By rotating the accelerator operating lever 28 clockwise around a pivot point 30, the accelerator operating lever can be rotated. 2
9 is configured to drive the accelerator of the engine E via the push-pull cable 26 by rotating counterclockwise about the pivot point 31.

The operation of the operating lever mechanism and accelerator operating mechanism configured as described above will be explained.

First, when the handle 12 of the operating lever 4 of the switching valve 2 in the neutral position is rotated to the right or left, the spool 6 of the switching valve 2 is operated, and this switching valve is switched. The protrusion 17 and links 18, 19, one end side 18a, which are provided on the rod 5, so that the accelerator is activated when the switching valve is substantially switched (when the stroke of the spool 6 reaches 4 mm), 19a, and configure the accelerator to start blowing when the actuator reaches its maximum speed by switching the switching valve.This allows the operation lever 4 to drive the accelerator from the middle. The stroke end position of the spool 6 (FIG. 5 B or D) is reached. When further operating force is applied to the handle 12 of the operating lever 4 from this position, the spool 6 has already reached the stroke end, so it does not operate, and only the operating lever 4 overcomes the elastic force of the spring 13 and the pivot pin 8 It will rotate around (Figure 5 E or A). Then, the rod 5 moves further to the left or right, and the protrusion 17 further moves to the one end side 18a of the link 18 or 19.
Alternatively, by continuing to press 19a, the accelerator is further driven and the speed of the actuator is increased. That is, to explain this in detail, in FIG. 4, when the operating lever 4 is rotated clockwise, the switching valve 2 is switched, and at the same time, the rod 5 is moved to the left. Move to. Although the spool has not completely reached the end of its stroke, the protrusion 17 provided on the rod 5 moves to the link 18 at a point in time when the switching valve has substantially switched, which is in the middle of the stroke.
The link 18 is rotated clockwise around the pin 20. This rotation is transmitted to link 19 via pin 22, and link 1
9 rotates counterclockwise. Then this link 1
The pin 21 located approximately in the middle of 9 also rotates counterclockwise,
This counterclockwise rotation of the pin 21 is transmitted to the accelerator drive unit 27 of the engine E through the link 23, link 24, rotation link 25, and push-pull cable 26, increasing the operating speed of the crane. It is. Conversely, when the rod 5 moves to the right and the protrusion 17 comes into contact with one end 19a of the link 19, this link 19 rotates counterclockwise together with the pin 21, and the counterclockwise rotation of this pin 21 The rotation is transmitted to the accelerator drive section 27 in the same manner as described above, and the operating speed of the crane is increased.

By the way, when the operating force applied to the handle 12 is weakened in the states A and E of FIG. 5, the operating lever 4 returns to its original position by the force of the spring 13 (FIGS. B and D). If the control lever 4 is further rotated from this state, it will return to the neutral position (Fig. C), but if the spool 6 of the switching valve 2 is of the spring return type, the handle 12 should be released in this state. It will return to the neutral position (Figure C) on its own.

As described above, the present invention is a construction machine that operates an actuator by switching the pressure oil from a hydraulic pump driven by an engine using an oil passage switching valve, and in which the switching operation of a spool that switches the oil passage of the oil passage switching valve is performed. In a construction machine that is operated by an oil passage switching valve that has a characteristic that the oil passage is substantially switched midway through and the speed of the actuator is maximized, the operating lever device that switches the oil passage switching valve is mounted on a pivot located at a fixed position. It is rotatably supported on a support pin, and the engaging part provided on one end engages with the spool of the oil passage switching valve to operate this spool and allow the oil passage switching valve to rotate to the switching stop position. an operating link rotatably supported on the pivot pin; and an operating link having one end attached to the operating lever and the other end connected to an accelerator drive section of the engine via a link mechanism. , a spring interposed between the link and the operating lever to restrict relative rotation of the link around the pivot pin and the operating lever; When the link rotates around the pivot pin together with the operating lever via the spring, the spool of the oil passage switching valve rotates to a switching stop position, and from this switching stop position, the operating lever The spring force of this spring is set so that the chisel rotates around the pivot pin against the spring, so that when the operating lever is used to switch the oil passage switching valve and operate the actuator, this oil passage switching valve is set. From the operating position of the operating lever at or near the operating position where the valve is substantially switched and the actuator speed is maximum, the operating lever is also used to drive the accelerator of the engine to further increase the actuator speed. After the actuator is gradually operated by one operation lever, the speed of the actuator is gradually increased, so the operation is simple and a wide range of continuous speed control from low speed to high speed can be performed. In addition, since the pivot part of the link for switching the spool of the oil passage switching valve and the pivot part of the lever part of the operating lever are configured with a common pin,
This also has the effect that the direction in which the oil passage switching valve is operated by the operating lever always coincides with the direction in which the accelerator is driven, making the operation easy to perform.

[Brief explanation of drawings]

FIG. 1 is a graph showing the control characteristics of the actuator actuator in a conventional construction machine, etc., FIG. 2 is a graph showing the control characteristics of the actuator actuator in the construction machine, etc. according to the present invention, and FIG. A schematic overall configuration diagram of a crane, which is an example of construction machinery, etc. to which the present invention is applied, FIG. 4 shows the main part of FIG. 3, and FIG. It is a diagram. DESCRIPTION OF SYMBOLS 1... Crane, 2... Oil passage switching valve, 4... Operation lever, 5... Rod, 7... Link, 11... Lever part,
16... Operating link, 17... Projection, 18, 19,
23, 24...link, 25...rotation link, 26...
Bushable cable, 27...Accelerator drive unit.

Claims (1)

[Claims] 1 A construction machine that operates an actuator by switching pressure oil from a hydraulic pump driven by an engine by an oil passage switching valve 2, the oil passage switching valve 2
In a construction machine that is operated by an oil passage switching valve 2 having a characteristic that the oil passage is substantially switched during the spool switching operation to switch the oil passage of the oil passage, and the speed of the actuator is maximized, the oil passage switching valve 2
An operating lever device for switching is rotatably supported on a pivot pin 8 located at a fixed position, and an engaging portion provided at one end engages with a spool 6 of the oil passage switching valve 2, so that the spool 6 a link 7 that can be rotated to the switching stop position of the oil passage switching valve 2 by operating the oil passage switching valve 2; and an operating lever 4 rotatably supported on the pivot pin 8;
An operating link 16 whose one end is attached to the operating lever 4 and whose other end is connected to the accelerator drive section of the engine via a link mechanism, and the relative relationship between the link 7 around the pivot pin 8 and the operating lever 4. This link 7 and operation lever 4 are used to restrict rotation.
and a spring 13 interposed between the link 7 and the spring 13 when the operating lever 4 is rotated around the pivot pin 8.
The spool 6 of the oil passage switching valve 2 rotates together with the operating lever 4 around the pivot pin 8 to the switching stop position, and from this switching stop position, only the operating lever 4 resists the spring 13. The spring force of the spring 13 is set so that it rotates around the pivot pin 8, so that when the operating lever 4 switches the oil passage switching valve 2 to operate the actuator, the oil passage switching valve 2 The actuator speed is further increased by driving the accelerator of the engine with the operating lever 4 from the operating position of the operating lever 4 at or near the operating position where the operating lever 4 is substantially switched and the actuator speed is maximum. Features: Actuator operating device for construction machinery, etc.