JPS6215335Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a speed control device for a self-propelled working machine such as a power shovel or a self-propelled crane.

In recent years, there has been a trend towards regulating the noise emitted by self-propelled working machines in urban areas, but the engine operating noise is a very large factor in this noise, and each part of the working machine is ultimately driven by the engine. Therefore, by suppressing the engine speed to a certain intermediate speed or lower, the noise generated by the self-propelled work machine can be kept within the permissible range. Since no output is required, there is no problem in terms of work functionality.

The present invention is designed so that the engine speed cannot be increased above a certain intermediate speed when the operating lever of the crawler traveling device is not operated, and the engine speed can be increased to the maximum speed only when the operating lever is operated. The purpose is to reduce noise while also enabling high-speed movement in vast work sites.

This invention provides speed control in a self-propelled working machine in which the control lever of the crawler traveling device on both sides, which is always activated to return to the drive stop position, and the remote control part of the engine speed control lever are installed on the chassis so that they can be operated simultaneously. A stopper engaging portion 32 is protruded and fixed in the middle of the transmission rod 22 between the lever and its remote control part, and the engaging surface 32a perpendicular to the transmission rod is the movable side of the stopper engaging portion when the engine speed increases. A stopper 3 is provided at the terminal, and the amount of protrusion of the stopper engaging portion is gradually reduced from the moving terminal to the terminal on the opposite side, and the stopper 3 slidably contacts the engaging surface at a constant intermediate speed position.
3 is always energized to return to the engaged position and attached to the vehicle chassis, and is interlocked with the operating lever so that the stopper is slid to the disengaged position from the stopper engaging portion when the operating lever of the crawler traveling device is operated. The vehicle is characterized by a stopper release device that is operated by the vehicle chassis.

The embodiments shown in FIGS. 1 to 5 in which the present invention is applied to a hydraulic power shovel will be described below. Reference numeral 1 denotes a vehicle platform rotatably mounted on the support frames of the crawler traveling devices 2, 2 on both sides; 3 indicates a boom cylinder for lifting up a boom 4 whose base end is pivoted to the vehicle platform 1; 5;
7 is an arm cylinder that rotates the arm 6 pivoted on the tip of the boom; 7 is a bucket cylinder that rotates the bucket 8 pivoted on the tip of the arm; 9 is the chassis 1;
In the upper driver's cab, reference numeral 10 indicates a high-speed diesel engine mounted on the chassis, and in the driver's cab 9 there are controls for operating directional control valves V1, V1 that respectively control the drive hydraulic motors of the crawler traveling devices 2, 2 on both sides. Lever 11,
11 and boom cylinder 3 control directional switching valve V2
, the operating lever 12 for the directional switching valve V3 for controlling the bucket cylinder 7, the operating lever 14 for the directional switching valve V4 for controlling the arm cylinder 5, and the operating lever 1 for the directional switching valve V5 for controlling the undercarriage swing hydraulic motor.
5 is pivoted by a shaft 16, and an operating member 17 having a foot-operated remote control section (accelerator pedal) that can be operated simultaneously with the operating section at the upper end of any of the operating levers is pivoted about a shaft 18.

Each operating lever 11, 12, etc. is connected at its lower end to the spool of the corresponding directional switching valve via a connecting rod 19, and each operating lever is stopped by a neutral position return spring in the directional switching valve as shown in the drawing. Of course, it is always activated to return to the neutral position. Reference numeral 20 designates a manual accelerator lever mounted in the driver's cab 9, and the accelerator lever 20 should also be able to be operated simultaneously with any of the aforementioned operating levers.

The operating member 17 is sequentially connected to a speed control lever 25 of a mechanical governor 24 of the engine 10 attached to the chassis 1 via pin-connected transmission members (transmission rods) 21, 22, and 23. is the support part 1a, 1 provided on the chassis 1
b, and the connecting portion of the transmission rod 23 to the speed control lever is a pin 26 fixed to the speed control lever 25 through an elongated hole 23a (FIG. 4) at the rear end of the transmission rod. The governor spring 28 The pin 26 of the speed control lever, which has returned to the idling position 0, is located at the rear end of the elongated hole 23a, and the elongated hole does not hold the transmission rod even if the speed control lever 25 is rotated from the idling position 0 to the maximum speed position M. 2
It has a length that prevents 2 from sliding.

Reference numeral 29 denotes a transmission rod that connects the lower end of the accelerator lever 20 and the speed control lever 25, and the rear end of the transmission rod 29 also has an elongated hole 29 that is exactly the same as the elongated hole 23a.
a, and the other end of the pin 26 is fitted into the elongated hole, and the accelerator lever 20 moves the speed control lever 25 from the idling position 0 to a certain intermediate speed position against the elasticity of the governor spring 28. The arc-shaped scale plate 3 is set so that it can only rotate up to N.
0, and the accelerator lever is fixed at any rotational position by a friction mechanism provided on the pivot portion 31 and the like.

Reference numeral 32 denotes a truncated conical stopper engaging portion which is screwed and fixed to the transmission rod 22 so that its axial position can be adjusted. Figure 3).
Therefore, the engaging surface 32a is provided at a moving end, ie, a front end, of the stopper engaging portion 32 at right angles to its movement trajectory when the engine speed increases. Nao 34
is a lock nut of the stopper engaging portion 32.

As mentioned above, the amount of overhang of the stopper engaging portion 32 relative to the transmission rod 22 is gradually reduced from the moving end to the opposite end when the engine speed increases, so that the engine returns from the maximum speed position to the idling position. This is to eliminate the possibility that the opposite end of the stopper engaging portion 32 engages with the stopper 33 and the return of the stopper engaging portion is prevented.

As shown in the figure, the stopper engaging portion 32 is configured in a truncated conical shape, and this is connected to the bolt-shaped transmission rod 22.
By screwing and fixing the stopper engagement portion to the transmission lever, the attachment position of the stopper engagement portion relative to the transmission lever can be adjusted after the device of the present invention is attached to the vehicle chassis.

The stopper 33 has an outer shape similar to a double rod-shaped piston, and the stopper slidably passes through a cylindrical guide 35 attached to the chassis 1 perpendicularly to the transmission rod 22, and is inserted into the guide 35. The attached spring 36 constantly urges the lower end claw-shaped portion 33a to return to the engagement position opposite the engagement surface 32a, and the two engage at a constant intermediate speed position N.

The stopper release device engages a pin 33b installed in the upper part of the stopper 33 with an elongated hole 38a at one end of a lever 38 pivoted to the chassis 1 by a shaft 37, and then engages the pin 33b on the plate-shaped arm 38b at the other end of the lever. , two inverted T-shaped levers 40 whose intermediate parts are pivoted 39 to the chassis 1 are brought into contact with each other, and connecting rods 41 are connected between the upper ends of both inverted T-shaped levers and the lower end extensions of the both-side operation levers 11. It is connected by .

The engine 10 drives two constant displacement hydraulic pumps of equal capacity, one of which supplies pressure oil to the directional control valves V1, V2, and V3 in the lower half of FIG. A hydraulic pump supplies pressure oil to the other directional valves V1, V4, V5.

The present invention has the above configuration, and when both of the operation levers 11 on both sides are in the drive stop position shown in the figure, the stopper 33 is held in the engagement position with the stopper engagement portion 32 by the elasticity of the spring 36, Inverted T-type lever 40
The lower end of the horizontal rod is in full contact with the plate-like arm 38b. Therefore, even if the operating member 17 is rotated forward (to the left in the figure) in this state, the speed control lever 25 can only be rotated until the engaging portion 32 engages with the stopper 33, that is, the speed control lever 25 can only be rotated to the N position. from,
When performing digging work by operating an operating lever other than the driving operating lever 11, the engine speed cannot be increased above a certain intermediate speed. Therefore, the noise generated during excavation work can be kept within an allowable range. If it is desired to keep the engine speed constant, the accelerator lever 20 may be rotated to a required position.

In addition, when the operation levers 11, 11 on both sides are rotated in the same direction or in opposite directions to operate forward, backward, or interlining rotation for traveling, the inverted T-shaped lever 40 that is interlocked with this By action, lever 38
Since the stopper 33 is always rotated about the shaft 37 to the position shown by the chain line in FIG. 1, the stopper 33 is pulled up to the detached position from the stopper engaging portion 32 via the pin 33b. Therefore, by rotating the operating member 17 fully forward, the speed control lever 25 can be rotated to the M position and the engine speed can be increased to the maximum speed, making it possible to move at high speed in a vast work site. .

Although the case where a manual stopper release device is provided between the operation lever 11 and the stopper 33 has been described above, the present invention is not limited to this, and also includes a case where a power stopper release device is adopted.

FIG. 6 shows an example of this, in which a stopper 33 that is to be slidably contacted with a stopper engaging portion 32 in a detachable manner is a single-acting cylinder 4 that is constantly biased to expand by a spring 42.
The cylinder chamber on the side through which the piston rod is inserted is connected to a fluid pressure source 45 such as hydraulic pressure or pneumatic pressure via an electromagnetic switching valve 44 which is always in a position communicating with the tank T or the outside air as shown in the figure. It is connected to the control lever 1 for driving.
1, the switch 4 is closed by a bell crank-shaped lever 38 that engages with an inverted T-shaped lever 40.
6 is inserted into the solenoid circuit 47 of the electromagnetic switching valve 44.

Therefore, when the operating lever 11 is rotated from the drive stop position to either the front or rear running position, the switch 46
is closed and the switching valve 44 is switched to the upper position in the figure,
The cylinder 43 contracts due to fluid pressure and the stopper 3
3 is pulled up to the detached position from the stopper engaging portion 32. Reference numeral 48 denotes a power source, and 49 denotes a spring for biasing the bell crank-shaped lever 38 against the inverted T-shaped lever 40. In FIG. 6, members given the same reference numerals as in FIG. 1 indicate corresponding members.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional side view of an embodiment of the present invention, Fig. 2 is a perspective view of the vicinity of the operating lever, Fig. 3 is a partially detailed view of Fig. 1, and Fig. 4 is taken along the line X-X in Fig. 1. A sectional view, FIG. 5 is a side view of the self-propelled working machine, and FIG. 6 is a longitudinal sectional side view of main parts of another embodiment. 1... Vehicle chassis, 2... Crawler traveling device, 10...
...engine, 11... operating lever of crawler traveling device, 17... operating member, 21, 22, 23... transmission lever, 24... mechanical governor, 25... speed control lever, 32... stopper engagement part, 32a...Engagement surface, 33...Stopper, 36
... Spring, 41, 40, 38 ... Stopper release device.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) The control lever of the crawler traveling device on both sides, which is always forced to return to the drive stop position, and the remote control part of the engine speed control lever are arranged on the vehicle chassis so that they can be operated simultaneously. In a self-propelled work machine, a stopper engaging portion 32 is provided in the middle of the transmission rod 22 between the speed control lever and its remote control portion.
is extended and fixed, and the engaging surface 3 is perpendicular to the transmission rod.
2a is provided at the movable end of the stopper engaging portion when the engine speed increases, and the overhang amount of the stopper engaging portion is gradually reduced as the end of the stopper engaging portion is on the opposite side from the movable end. A stopper 33 that slidably contacts the engagement surface in a detachable manner is always urged to return to the engagement position and is attached to the vehicle chassis, and the stopper is slid to the disengaged position from the stopper engagement portion when the operating lever of the crawler traveling device is operated. 1. A speed control device for a self-propelled working machine, characterized in that a stopper release device is attached to the vehicle chassis and operates in conjunction with the operating lever so as to move the operating machine. (2) The stopper engaging portion is configured in a truncated conical shape,
Utility model registration claim (1) in which this is screwed and fixed to a bolt-shaped transmission rod so that its axial position can be adjusted.
A speed control device for a self-propelled working machine as described in .