JPS6131632A - Speed change shock preventing apparatus - Google Patents

Abstract

PURPOSE:To permit the smooth speed change operation and improve workability by softening the shock on speed change by detecting the speed change operation and automatically reducing the number of engine revolution for a prescribed time after the detection point, particularly in a construction car. CONSTITUTION:If a speed change lever 9 is operated when an engine is operated, setting a fuel control lever 1 at a high-idle position III, one among limit switches 11-13 is turned ON, and a relay 16 is operated through an OR circuit 14 and a one-shot circuit 15, and an electric power source 17 is connected to an electromagnetic actuator 8 through a selecting switch 18. Therefore, a rod 8a is extended by a prescribed amount in the A direction, and one edge 7a of an elliptical hole on a yoke 7 is engaged with a pin 5a, and a governor lever 5 is pushed back, and the number of engine revolution is reduced by a fuel injection pump 6. At this time, the movement of the governor lever 5 is absorbed by a cylinder 4 having a loose spring 4a, and the lever 1 is set inoperative.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gear shift shock prevention device for preventing shocks during gear shifts of a construction vehicle.

[Conventional technology]

In general, construction vehicles such as bulldozers and dozer sitbels are
When shifting gears, if the gear shifting operation speed is high, or if shifting is performed in a place with many slopes, a large gear shifting shock occurs.

Conventionally, in order to prevent such a shift stirrup, the clutch engagement pressure was gradually increased using a modulation pulp (the clutch was engaged through a half-clutch state, and the
Alleviate stress. That's what I was doing.

[Problem that the invention seeks to solve]

However, if K is used to reduce the shift time as described above, there is a problem in that it causes early clutch wear and lengthens the time lag.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a shift shock prevention device that can solve the above-mentioned problems and alleviate shock during shift. [Means for solving the problem] According to the present invention, the operation of the gear shift lever is detected, and the engine rotation is reduced to slow speed or half rotation at a certain point from the time of this detection.

[For production]

Since the engine speed is lowered just before shifting, the shift shock can be reduced.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of the shift shock prevention device according to the present invention, and shows the state in which the fuel control lever 1 is at the stop position.

The operation amount of the fuel control lever 1 is determined by the rods 2, 3,
It is transmitted to the governor lever 5 via a link mechanism consisting of a cylinder 4 having a loose spring 4a. The fuel injection pump 6 supplies an amount of fuel corresponding to the rotational position of the Luna lever 50 to the injection nozzle of the engine (not shown), and the engine's rotational speed is controlled according to the amount of fuel injected.・The stop position (1) of the fuel control lever l corresponds to the position where the fuel injection pump 6 does not supply any fuel. Also, the positions (n) and (to) of the lever 1 indicated by broken lines are as follows: On the other hand, the governor lever 5 is connected to the rod 8a of the electromagnetic actuator 8 via the elongated yoke 7. This electromagnetic actuator 8 is controlled by a signal that commands low-speed rotation of the engine, which will be described later.When activated, the rod 8a is extended by a predetermined amount in the direction of arrow A, and one end 7a of the elongated hole of the elongated hole yoke 7 is connected to the governor lever 5. It operates so as to return it to the direction of the pin 5a. Note that the details will be described later.

As shown in the figure, the shift lever 9 can select three gears for both forward and forward movement.Inside the shift box 10, there are limit switches 11, 12, and 13 for detecting the operation of the shift lever 9. It is arranged. These limit switches 11, 12, and 13 are respectively disposed between each gear, and are turned on by the gear lever 9 when the gear lever 9 is operated and before the gear lever 9 reaches another gear selection position. .

The outputs of each limit switch 11, 12, 13 are logically summed by an OR circuit 14, and the output of the OR circuit 14 is applied to a Funcitat circuit 15. Therefore, when any of the limit switches 11, 12 and 13 is turned on, the one-shot recovery IEL
When either one of 12 and 13 is turned on, a single pulse corresponding to the time width required from that point on until the shift is completed is generated.

The relay 16 turns on its relay contact while the pulse is applied from the contact circuit 15, and the power supply (24V) is turned on.
1) is electrically connected to the electromagnetic actuator via the changeover switch 18.

Note that the changeover switch 18 is turned off when this function is not performed. As described above, the electromagnetic actuator 8 moves the rod 8a by a predetermined amount in the direction of arrow A while a current is applied from the power source 1).

Next, we will explain the action of the Kono transmission shock prevention device.

Now, move the fuel control lever 1 to the high idle position (
This section describes the case where the construction vehicle is operated with the setting set to
The high idle position (to) 2 general e1- and the 1st eggplant clear;
-~ Product East 1 N^↓The positional relationship of the cylinder 4 with the loose spring 4a, the governor lever 5, the elongated hole yoke 7, etc. is as shown in Fig. 2.At this time, the electromagnetic actuator 8 is activated. Therefore, the movement of the gaff 9/<-5, the electromagnetic actuator 8, and the elongated hole yoke 7 do not impose any mechanical restraints.

Here, when the gear shift lever 9 is operated, the electromagnetic actuator 8 extends the rod 8a by a predetermined amount in the direction of the arrow A, as described above, and extends the rod 8a by a predetermined amount to push the end 7a of the elongated hole of the elongated hole yoke 7 into a narrow position <-5. The governor lever 5 is engaged with the pin 5a of the lever 5 to push back the governor lever 5 (see FIG. 3).

In this way, the governor (-5) is rotated to a predetermined low speed rotation position and the engine speed is automatically reduced to a lower rotation than the idle speed. Further, at this time, the movement of the cylinder (-5) is absorbed by the cylinder 4 having the loose spring 4a, so that the rods 3, 2 and fuel control lever 1 do not operate.

Then, when the predetermined time required to complete the gear shift has elapsed and the electromagnetic actuator 8 is turned off, the rod 8a becomes free and the governor lever 5 is returned to its original position (Fig. 2) by the loose spring 4a, thereby controlling the fuel. engine rotation) will return to its original state.

In addition, to adjust the engine speed down, adjust the length of the rod 8a (the tip of the rod 8a is threaded,
(adjust the rod length with the lock nut 19) from K. Further, the actuator for extending and retracting the rod 8a is not limited to the electromagnetic actuator of this embodiment, but various types such as a hydraulic and pneumatic actuator can be used. Furthermore, the means for detecting when the gear shift lever is operated is not limited to a limit switch, and various other means such as a proximity switch can be considered. Furthermore, a timer relay may be used instead of the one-shot circuit of this embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, since the engine speed is lowered during gear shifting, it is possible to alleviate shocks during downshifting and upshifting. Because of its smooth gear shifting, Doza S/! With L-Pel, the load does not tip over even if you change gears before loading the dump truck. Also, unnecessary spinning of the legs when shifting the dozer peg or bulldozer is eliminated. Also,
Determining the engine speed when shifting gears 2! Since the modulator valve pressure can be reduced, the traction force can be increased.Furthermore, the shift shock is alleviated, which improves riding comfort.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the gear shifting prevention device according to the present invention, and FIG. 2 and FIG. 0 1... Fuel control lever, 4a - Loose spring, 4... Cylinder, 5... Guno (Nareno (-
16...Fuel injection pipe, 7...Elongated hole yoke, 8...
...Electric speed box, 11,12,13-...Limit switch, 14--OR circuit, 15--One-shot circuit, 16--Relay, 1)...Power supply.

Claims (3)

[Claims] (1) A detection means for detecting when the gear shift lever is operated; a signal output means for outputting a signal instructing low-speed operation of the engine for a certain period of time from the time of detection by the detection means; and a signal from the signal output means. A gear shift shock prevention device comprising a driving means for lowering the engine speed by the following steps. (2) The signal output means is a one-shot circuit that receives the detection signal from the detection means and generates a pulse signal with a fixed time width from the time of reception.
Shift shock prevention device described in ). (3) The driving means is connected to a governor lever of the engine through a long hole yoke to which the operating amount of the fuel control lever is mechanically transmitted via a loose spring, and when driving, the drive means connects the long hole yoke with the long hole yoke. Claim 1 comprising: an electromagnetic actuator that moves a certain amount in a direction; and a drive circuit that supplies a drive current to the electromagnetic actuator while receiving a signal from the signal output means.
The gear shift shock prevention device described in item 1).