JPH01262231A - Deceleration display of working machine - Google Patents

Abstract

PURPOSE:To display deceleration condition by providing at the outside of a working machine a display means provided for displaying deceleration condition, a pressure detecting means for detecting a circuit pressure on opposite side to pressure oil discharge direction of a hydraulic pump, a display driving means for operating the display means when the detected pressure exceeds a predetermined value. CONSTITUTION:A bi-directionally inclining rotary hydraulic pump 1 discharges the pressure oil in either one direction according to a switching means 10. Thereby a hydraulic motor 3 is driven to drive an inertia body. At deceleration, the pressure is produced in a pipe line on the opposite side to the discharge direction of the hydraulic pump 1 by pumping operation of the hydraulic motor 3. This pressure is detected at a pressure detecting means 23 and when its detected value exceeds a predetermined value, a display driving means 50 operates a display means 25 to display deceleration condition. As the display means 25 is provided outside of a working machine the deceleration condition can be recognized from outside of the working machine.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of Application The present invention is used in working machines such as hydraulic excavators that drive inertial bodies such as lower traveling bodies or upper revolving bodies by means of hydraulic closed circuits, and is used to control the running deceleration state and The present invention relates to a deceleration display device that notifies a following work machine or a work machine working adjacently of a turning deceleration state.

B. Prior Art FIG. 5 shows a hydraulic closed circuit for this type of working machine. A pair of ports of the double tilting hydraulic pump 1 are a pipe line 2A and a pipe line 2B.
is connected to a pair of ports of the hydraulic motor 3 to form a hydraulic closed circuit. A speed reduction device 4 is connected to the output shaft of the hydraulic motor 3, and wheels 6 are attached to a propeller shaft 4a extending from the speed reduction device 4 via a differential gear box 5. The operating member 6 is, for example, a pedal or a lever, and controls the rotational speed of the engine 7 and operates the pressure reducing valve 9 via the spring 8 to obtain a hydraulic pressure from the pressure reducing valve 9 that is proportional to the amount of lever operation. This pressure oil is sent to the regulator 11 via the forward/reverse switching valve 10, and controls the discharge flow rate of the double tilting hydraulic pump 1-.

Now, when the forward/reverse switching valve 10 is switched to the F position and the operating member 6 is operated, the rotational speed of the engine 7 increases and the pressure oil from the pressure reducing valve 9 is transferred to the cylinder chamber 11 of the regulator 11.
F, the double tilting hydraulic pump 1 discharges pressure oil at a flow rate corresponding to the amount of operation of the operating member 6 to the conduit 2A. As a result, the hydraulic motor 3 rotates in the direction of the arrow, the axle 6 rotates, and the vehicle moves forward at a predetermined speed.

When the operating member 6 is released while the vehicle is traveling at a predetermined speed, the operating member 6 is returned to the neutral position by the spring 8, and the engine speed decreases, and the discharge flow rate of the double tilting hydraulic pump 1 decreases. The vehicle uses its inertia force to drive the hydraulic motor 3 in an attempt to travel at the same speed. As a result, the hydraulic motor 3 discharges pressure oil into the pipe line 2B and rotates the double tilting hydraulic pump 1.

The engine 7 is driven. As a result, engine braking is applied and the vehicle decelerates.

In FIG. 5, 12 is a valve block equipped with a flushing valve, a leaf valve, etc., and 13 is a hydraulic pressure source for the operating system.

Problems to be Solved by the C0 Invention In hydraulically driven vehicles that run on hydraulic closed circuits, engine braking is greater than in vehicles that use a general 1-rucon or gears, and in particular, it is difficult to operate. The rotation speed of the engine 7 and the double tilting hydraulic pump are determined by the member 6.
When controlling both of the discharge flow rates, the engine brake is extremely strong.

Therefore, when driving on a public road, if the amount of operation of the operating member 6, such as the accelerator pedal, is reduced, there is a problem in that even though the vehicle speed suddenly decelerates, this is not reported to the following vehicle. .

Such a problem may similarly occur in a working machine that uses a hydraulic closed circuit in its swing device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a deceleration display device for a work machine that displays the deceleration state of running or turning due to engine braking.

To explain with reference to FIG. 1 showing an embodiment of the means for solving the D0 problem, the deceleration display device for a working machine according to the present invention is a dual tilting hydraulic system capable of discharging pressure oil to either of a pair of ports. pump 1 and the hydraulic pump 1
The present invention is applied to a deceleration display device for a working machine, which includes a hydraulic motor 3 that drives an inertial body that is connected in a closed circuit to an output shaft, and a switching means 10 that switches the discharge direction of the double tilting hydraulic pump 1. The above-mentioned problem is caused by the display means 25 provided outside the working machine to display the deceleration state, and the switching means 1.
A pressure detection means 23 detects the circuit pressure on the side opposite to the pressure oil discharge direction of the hydraulic pump 1 switched by 0, and a display means 25 is activated when the pressure detected by this pressure detection means 23 exceeds a predetermined value. This problem can be solved by providing a display driving means 50 for causing the problem to occur.

The E0 action double tilting hydraulic pump 1 discharges pressure oil in either direction according to the switching means 10. As a result, the hydraulic motor 3 is driven and the inertial body is driven.

During deceleration, pressure is built up in the pipe line on the opposite side to the discharge direction of the hydraulic pump 1 due to the pumping operation of the hydraulic motor 3. This pressure is detected by the pressure detection means 23, and when the detected value exceeds a predetermined value, the display drive means 50 causes the display means 25 to
is activated and the deceleration state is displayed. Since the display means 25 is provided outside the working machine, the deceleration state can be recognized from outside the working machine.

In the above-mentioned sections and section E, which describe the present invention in detail, figures of embodiments are used to make the present invention easier to understand, but the present invention is not limited to the embodiments.

F. Example 1.First embodiment- FIG. 1 shows a first embodiment of the invention. In addition.

In the following description, parts similar to those in FIG. 5 are designated by the same reference numerals.

The switching valve 21 is switched to the F position when the forward/reverse switching valve 10 is switched to the F position, and to the R position when the forward/reverse switching valve 10 is switched to the R position, by the switching pilot pressure of the forward/reverse switching valve 10. When switched to the F position, the pressure oil in the pipe 2B on the opposite side to the discharge direction of the double tilting hydraulic pump 1 is taken out to the pilot pipe 22, and when switched to the R position, the pressure oil is taken out from the pipe 2B on the opposite side to the discharge direction of the double tilting hydraulic pump 1.
Pressure oil A is taken out to the pilot pipe line 22. At the end of the pilot line 22, the line pressure of the line 2A and the line 2B,
That is, a pressure switch 23 is provided that closes when the pressure in the pilot line 22 exceeds a predetermined value. Here, this predetermined value is a value based on the pressure that stands in the motor return side pipe during deceleration.

This pressure switch 23 is interposed between a battery 24 and an indicator light 25, and when the pressure switch 23 is closed, power is supplied from the battery 24 to the indicator light 25, and the indicator light 25 lights up.

Further, a brake switch 26 that closes when a brake pedal (not shown) is operated is provided in parallel with the pressure switch 23, and when the brake switch 26 is closed, an indicator light 25 lights up.

27F and 27R are pilot pipes that guide the hydraulic pressure outputted by operating a lever for selecting forward/reverse travel to the forward/reverse switching valve 10 and the picot 1 port of the switching valve 21.

Now, turn the forward/backward switching valve 10 to F using the forward/backward lever (not shown).
When switched to the F position, the switching valve 21 is also switched to the F position. When the operating member 6 (not shown) is operated in this state, the engine speed increases and pressure oil is introduced into the cylinder chamber 11F on the right side of the regulator 11, and the double-swivel hydraulic pump 1 is operated in accordance with the operating amount of the operating member 6. A flow rate of pressure oil is discharged to the pipe line 2A.

The hydraulic motor 3 is driven by this pressure oil, and the vehicle travels. At this time, the pressure oil (charge pressure) in the return side pipe line 2B of the hydraulic motor 3 is applied to the switching valve 21. The pressure switch 23 is guided through the pilot line 22 to the pressure switch 23.
The pressure switch 23 remains open because the set pressure has not been reached.

When the operation of the operating member 6 is stopped, the engine speed decreases and the discharge flow rate of the double tilting hydraulic pump 1 also decreases, and as described above, a large engine brake is applied by the hydraulic closed circuit, and the vehicle suddenly decelerates.

At this time, a pressure much higher than the charge pressure is generated in the pipe line 2B, and the switching valve 21. A pressure switch 23 is closed via the pilot line 22. As a result, the display drive circuit 50 of battery 24→pressure switch 23→indicator light 25→ground is formed, the indicator light 25 lights up, and the following vehicle is notified that the vehicle is decelerating. When the brake switch 26 is closed by the brake operation, the indicator light 25 lights up as usual. The same holds true when the forward/reverse switching valve 10 is switched to the R position.

1.Second embodiment- 2 and 3 show a second embodiment of the invention.

Pipe line 2 connected to a pair of ports of the double tilting hydraulic pump 1
A, pressure switch 31A, pressure switch 31 in pipe line 2B
B are provided respectively. These pressure switches 31A
, 31B are turned on at a pressure higher than the normal charge pressure, that is, at a pressure in the conduit on the motor return side during deceleration. On the other hand, the forward/reverse switching valve 32 is an electromagnetic switching valve, and is switched to the F position or the R position by the forward/reverse switching switch 33. As shown in FIG.
has an F terminal that closes when forward movement is selected and an R terminal that closes when reverse movement is selected. A pressure switch 31B on the conduit 2B side is interposed between the F terminal and the indicator light 25.
A pressure switch 31A on the conduit 2A side is interposed between the two. These switches 31A, 31B, and 33 are provided in parallel with the brake switch 26.

As mentioned above, for example, when the operating member 6 is stopped while the vehicle is moving forward and the vehicle decelerates, the pressure switch 31B of the conduit 2B is closed, so that the battery 24 → F terminal of the forward/reverse selector switch 33 → the pressure switch 31B → the indicator light. 25 display drive circuits 50A are formed, and the indicator light 25 lights up. Since the pressure switch 31A of the conduit 2A is closed in the same way while traveling in reverse, the battery 24 → R terminal of the forward/reverse selector switch 33 → the pressure switch 31A → the display drive circuit 50 of the indicator light 25
B is formed and the indicator light 25 lights up. Note that the reference numeral 34 in FIG. 3 is a diode for preventing current backflow, and prevents a switching signal from flowing to the forward/reverse switching valve 32 when the brake switch 26 is closed.

- Third Embodiment - FIG. 4 shows a display control circuit diagram that achieves the same functions as FIGS. 1 and 2 in combination with the circuit configuration of FIG. 2. The same parts as in FIGS. 2 and 3 will be described with the same reference numerals.

Brake switch 26 is connected to OR gate 41. The output terminals of AND gates 42 and 43 are also connected to the OR gate 41. The F terminal of the forward/reverse changeover switch 33 and the pressure switch 31B are connected to the AND gate 42, and the R terminal of the forward/reverse changeover switch 33 and the pressure switch 31A are connected to the AND gate 43, respectively. The output terminal of the OR gate 41 is connected to the base of the switching transistor 44. This switching transistor 44 is interposed between the indicator light 25 and the ground, and when the switching transistor 44 is turned on, the battery 24 → the indicator light 25 → the switching 1 range star 44
→A grounded display drive circuit 50 is formed and the indicator lamp 25 lights up.

That is, (1) When the brake switch 26 is turned on, the indicator light 25 lights up.

(2) When the F terminal of the forward/reverse changeover switch 33 is turned on and the pressure switch 31B is turned on, the indicator light 25 lights up.

(2) When the R terminal of the forward/reverse changeover switch 33 is turned on and the pressure switch 31A is turned on, the indicator light 25 lights up.

The logic gate shown in FIG. 4 can also be configured by software using a microcomputer.

Note that although the case where both the engine rotation speed and the pump discharge flow rate are controlled simultaneously by operating the operation member 6 has been described above, the present invention can also be applied to a case where the engine rotation speed is controlled by a separate operation member. Moreover, although the case where deceleration display is performed for the travel hydraulic drive circuit has been described above, the present invention can also be applied to a swing hydraulic drive circuit.
In this case, the rapid deceleration of the turning speed can be recognized from the outside of the work machine, improving the safety of on-site work.

G0 Effects of the Invention According to the present invention, the sudden deceleration of the inertial body driven by a hydraulic closed circuit is displayed on the display means provided outside the working machine, for example, on the rear surface of the traveling vehicle, so that the following vehicle can see the sudden deceleration. can tell when the vehicle in front of them is suddenly slowing down.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention. 2 and 3 show a second embodiment, in which FIG. 2 is a hydraulic circuit diagram and FIG. 3 is an electric circuit diagram of an indicator light. FIG. 4 is a block diagram of an indicator light control circuit showing a third embodiment. FIG. 5 is a traveling hydraulic drive circuit diagram showing a conventional example. 1: Double tilting hydraulic pump 2A, 2B: Pipe line 3: Hydraulic motor 6: Operating member 9: Pressure reducing valve 1
0: Forward/forward switching valve 11: Regulator 21: Switching valve 23: Pressure switch 25: Indicator light 26: Brake switch

Claims (1)

[Scope of Claims] A double tilting hydraulic pump capable of discharging pressure oil to either of a pair of ports, a hydraulic motor driving an inertial body connected to the hydraulic pump in a closed circuit and connected to an output shaft; A deceleration display device for a work machine, comprising a switching means for switching the discharge direction of a double tilting hydraulic pump, comprising: a display means provided outside the work machine for displaying a deceleration state; and a control hydraulic pump switched by the switching means. pressure detection means for detecting circuit pressure on the side opposite to the pressure oil discharge direction; and display drive means for operating the display means when the pressure detected by the pressure detection means exceeds a predetermined value. Features: A deceleration display device for work equipment.