JPH04334628A - Speed change control device for tractor shovel - Google Patents

Abstract

PURPOSE:To simply perform not only changeover of vehicle speed at forward run plunging but running operation at backward run. CONSTITUTION:When a forward run switch is ON and a second shift step switch 2nd is ON, and a down shift 5 is ON in this condition, a second shift step solenoid 2 is changed over to a first shift step solenoid 1 and a hydraulic clutch for a first shift step is actuated. When a forward/backward lever is changed over to the backward position, a shift down function is released. When the forward/backward lever is set to the backward position, the shift down function is exhibited as well. When driving force is demanded at backward run in such case of working at a front down place, by pushing the down shift 5, the tractor is run at first shift step.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed change control device for a tractor shovel.

0002

2. Description of the Related Art In a conventional tractor shovel, an engine is provided at the rear of the vehicle body, and a transmission for transmitting the driving force of the engine is located at the center of the lower part of the vehicle body. The shift control lever for controlling the transmission is provided separately from the shovel operating control lever, regardless of whether it is mechanical or electrical.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned conventional case, the vehicle is moved forward toward the earth and sand, and the vehicle is operated in second gear until just before the plunge. The shovel operation control lever must be operated at the same time as switching from speed to first speed. Furthermore, when going backwards, it was necessary to switch from first gear to second gear. However, this work was complicated and required skill.

The present invention has been made to solve the above-mentioned drawbacks, and it is possible to change the vehicle speed during forward thrusting while operating the shovel operation control lever, thereby simplifying the driving operation when reversing. The purpose is to provide equipment.

[0005]

[Means for Solving the Problem] As shown in FIGS. 1 and 2, the means for solving the problem according to claim 1 of the present invention is as shown in FIGS. The ON signal cuts off the power to the electromagnetic operated valve 2 for the first speed stage (second speed stage in the example),
Electromagnetically operated valve 1 for the second speed stage (first speed stage in the example)
a shift down means for supplying current to the shift down means; a maintenance means for maintaining the downshift state regardless of the ON signal of the downshift switch 5 when the down shift means is in operation; Forward switch F
The electromagnetic operated valve 1 for the second speed gear is energized by a switching signal from one of the reverse switches R to the other, or a switching signal from the first speed switch 2nd to the other speed switch. It is provided with a release means for energizing the electromagnetically operated valve 2 for the first speed stage.

[0006] The problem solving means according to claim 2 is as shown in FIGS.
As shown in the figure, the ON signal of the first speed gear switch 2nd and the downshift switch 5 cuts off the power to the electromagnetic operated valve 2 for the first speed gear, and turns it on to the electromagnetic operated valve 1 for the second speed gear. The downshift means is energized, and when the downshift means is in operation, a switching signal from one of the forward switch F and reverse switch R to the other, an ON signal of the downshift switch 5, or the first speed gear is transmitted. By the switching signal from switch 2nd to other speed stage switches,
It is provided with a release means for cutting off the energization to the electromagnetically operated valve 1 for the second speed gear and energizing the electromagnetically operated valve 2 for the first speed gear.

The means for solving the problem according to claim 3 is shown in FIGS.
As shown in the figure, the ON signal of the first speed gear switch 2nd and the downshift switch 5 cuts off the power to the electromagnetic operated valve 2 for the first speed gear, and turns it on to the electromagnetic operated valve 1 for the second speed gear. When the downshift means is energized and the downshift means is in operation, the second speed is changed by an on signal from the downshift switch 5 or a switching signal from the first speed switch 2nd to another speed switch. It is provided with a release means for cutting off the energization to the electromagnetically operated valve 1 for the speed gear and energizing the electromagnetically operated valve 2 for the first speed gear.

[0008]

[Operation] In the problem solving means according to claim 1, when the speed gear lever is set to the 2nd gear position, the 2nd gear gear switch 2n
d is turned on, the circuit power is turned on, and in this state, when the downshift switch 5 is turned on, the second speed solenoid actuated valve 2 is switched to the first speed solenoid actuated valve 1, and the first speed fluid pressure clutch is activated. It turns out.

After this, since the signal "H" from the output terminal Q of the control section 9 is input to the clock terminal CK of the control section 9, the clock terminal CK remains "H" due to the maintaining means, and is returned to its original position. There is no change in the state even if the downshift switch 5 is pressed again.

Next, when the forward/reverse lever is switched to the rear position or when the first speed switch 2nd is switched to another speed switch, the downshift function is canceled by the release means.

The above operation is performed when the forward/reverse lever is in the forward position, but a similar downshift function is achieved when the forward/reverse lever is in the rear position. Therefore, when driving force is required when reversing, such as when working in a location where the vehicle is tilted forward, it is sufficient to press the downshift switch 5 to drive.

[0012] In the problem solving means according to claim 2,
The circuit power is turned on only by turning on the 2nd speed stage switch 2nd. Since the output terminal Q of the control section 9 is not connected to the clock terminal CK, as shown in FIG. The clock terminal CK will change. Therefore, the downshift function is turned on.
It will be off and on again.

[0013] In the problem solving means according to claim 3,
As shown in FIG. 5, the circuit power is turned on only by turning on the two-speed gear switch 2nd. Then, when the downshift switch 5 is turned on, the gear is shifted down, but from then on, the signal at the clock terminal CK changes every time the downshift switch 5 is pressed until the 2nd speed switch 2nd is turned off. The downshift function turns on and off.

Further, even if the forward/reverse switches F and R are switched, the state does not change because no signal is input. in this case,
The downshift function is performed regardless of the position of the forward/reverse lever, so the downshift function is performed even when driving in reverse.

Therefore, when driving forward, turning on the downshift function, scooping up dirt with the bucket, and reversing, the driver has to decide whether to activate the downshift function or not depending on the condition of the road surface. All you have to do is decide. For example, if the road surface is flat, pressing the downshift switch 5 to move backward will drive the vehicle in second gear. Furthermore, when the road surface slopes forward, if the vehicle moves backward without pressing the downshift switch 5, the vehicle can travel in first gear and obtain a large driving force.

[0016]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

(First Embodiment) FIG. 1 is an electric circuit diagram of a speed change control device according to a first embodiment of the present invention, and FIG. 2 is a control flowchart thereof.

As shown in the figure, in the tractor shovel speed change control device according to the present invention, manual switching of the transmission for controlling vehicle speed is performed by engaging and connecting a plurality of fluid pressure clutches, and each fluid pressure clutch is actuated independently. A plurality of electromagnetically operated valves 1
. A downshift switch 5 (DSS switch 5) is provided for switching to energize the electromagnetically operated valve 1.

[0019] The fluid pressure clutch and the electromagnetically operated valve include:
There are clutches for 1st to 4th gears, and even for forward and backward travel, but in this example, the focus is on switching from the 2nd gear fluid pressure clutch to the 1st gear fluid pressure clutch, so the 1st gear clutch is
Only the electromagnetically operated valves 1 and 2 corresponding to the speed hydraulic clutch and the second speed hydraulic clutch are shown, and the others are omitted. Furthermore, when the electromagnetically actuated valves 1 and 2 are switched, the pressure oil in the hydraulic circuit flows to the corresponding hydraulic clutch and connects the clutch. Since this hydraulic circuit is also well known, its explanation will be omitted.

The gear change switch group 3 also includes speed gear switches 1st to 4th corresponding to 1st to 4th gears;
It consists of forward/reverse switches F and R, which can be switched using the gear shift lever and the forward/reverse lever.

The downshift switch 5 is of a push button type, and is provided in the grip of the cargo handling control lever, and when the push operation is released, the downshift switch 5 returns to its original position by the biasing force of a spring.

The control circuit 6 for controlling the electromagnetically operated valves 1 and 2 includes a forward switch F, a reverse switch R,
When the circuit power is turned on to the 2nd speed gear switch and the on signal of the downshift switch 5, the 2nd gear solenoid operated valve 2 is activated.
A shift down means that cuts off the power to the first speed gear electromagnetic operated valve 1 and supplies power to the first speed solenoid actuated valve 1, and a maintenance device that maintains the down shift state regardless of the ON signal of the down shift switch 5 when the down shift means is operating. and when the downshift means is operating, a switching signal from one of the forward switch F and reverse switch R to the other, or a switching signal from the two speed switch to the other speed switch causes It is provided with a release means that cuts off the power to the electromagnetically operated valve 1 for the speed gear and energizes the electromagnetically operated valve 2 for the second speed gear.

That is, as shown in FIG. 1, the control circuit 6 has input terminals C, D, G, E, F and output terminals I, K, L, J.
The first speed switch 1st is connected to the input terminal C, and its input signal is directly output to the output terminal J of the first speed solenoid operated valve. Further, a two-speed gear switch 2nd is connected to the input terminal D, and its input signal is input to the constant voltage circuit 7. A forward switch F is connected to the input terminal G.
When the forward switch F is connected, power is supplied from the 24V power supply circuit to the relay coil RL2, so that the relay contact 8 is driven. A capacitor C1 is connected to the NC contact of this relay contact 8, a capacitor C2 is connected to the NO contact, and a clear terminal CLR of the control section 9 is connected to these circuits. A downshift switch 5 is connected to input terminals E and F, and this input terminal E is connected to the base terminal of a transistor 10.
The collector side of 0 is connected to the clock terminal CK of the control section 9.

The control section 9 has a preset terminal PR, output terminals Q, Q1, and an input terminal D in addition to the above-mentioned terminals. A relay coil RL1 is connected to the output terminal Q via a transistor 11, and its relay contact 12 has a
Terminal K of the second speed solenoid operated valve 2 and terminal J of the first speed solenoid operated valve 1 are connected, respectively. Furthermore, the output terminal Q is also connected to the clock terminal CK of the control section 9.

In the control section 9, the clear terminal CLR
When becomes "L", it is cleared, "L" signal is output from output terminal Q, and "H" signal is output from output terminal Q1 (output terminals Q and Q1 output signals opposite to each other). . The signal at the output terminal Q1 is input to the input terminal D. Also, when the preset terminal PR becomes "L", the preset is performed, the output terminal Q becomes "H", and the output terminal Q1 becomes "L".
" is output. Also, the clock terminal CK changes from “L” to “
The signal at terminal D is output from output terminal Q only when the output terminal rises to "H". Therefore, when the input terminal D is at "H" and the clock terminal CK rises from "L" to "H", an "H" signal is output from the output terminal Q.

The operation of the above configuration will be explained based on FIG. 2. When the forward/reverse lever is in the forward position, the forward switch F
is turned on, and when the speed gear lever is moved to the 2nd gear position, the 2nd gear gear switch is turned on, the circuit power is turned on, and the capacitor C is turned on.
1 is charged, the clear terminal CLR of the control section 9 rises with a delay, the control section 9 is cleared, and the output terminal Q outputs "L". Therefore, the transistor 11 is turned off and the relay coil RL1 is demagnetized, so the output terminal K
conducts, the second speed solenoid operated valve 2 is driven, and the second speed hydraulic clutch is operated. At this time, since the output terminal Q of the control section 9 is "L", the output terminal Q1 is "H", and the input terminal D is "H".

In this state, downshift switch 5 (D
When the SS switch is turned on, the transistor 10 is turned on and the clock terminal CK of the control section 9 rises to "H". As the clock terminal CK rises from "L" to "H", the "H" signal of the input terminal D is output from the output terminal Q, so the transistor 11 is turned on, and the relay coil RL1 is energized, resulting in a two-speed Stage solenoid operated valve 2 to 1
The speed gear electromagnetic operated valve 1 is switched to operate the first gear fluid pressure clutch.

After this, since the "H" signal from the output terminal Q is input to the clock terminal CK of the control section 9, the clock terminal CK remains "H" and the downshift switch 5 returns to its original position. Pressing again does not change the status.

Next, when the forward/reverse lever is switched to the rear position and the forward/reverse switch is changed from F to R, relay coil RL2
is demagnetized, relay contact 8 is switched, and capacitor C2
Since charge is stored in the clear terminal CLR of the control unit 9
becomes “L” for a certain period of time. Therefore, output terminal Q is “L”
Therefore, the downshift function will be canceled (D
SS release).

Although the above operation has been described with respect to the downshift function when the forward/reverse lever is in the forward position, a similar downshift function is also achieved when the forward/reverse lever is in the rear position. Therefore, when driving force is required when reversing, such as when working in a location where the vehicle is tilted forward, it is sufficient to press the downshift switch 5 to drive.

(Second Embodiment) FIG. 3 is an electric circuit diagram of a speed change control device according to a second embodiment of the present invention, and FIG. 4 is a control flowchart thereof.

As shown in the figure, the speed change control device of this embodiment is as follows:
Compared to the speed change control device of the first embodiment shown in FIG. 1, the output terminal Q of the control section 9 is not connected to the clock terminal CK, and the other configurations are the same as those of the first embodiment.

In the above configuration, as shown in FIG. 4, when the downshift switch 5 is released from being pressed after the downshift function is activated, the clock terminal CK goes down from "H" to "L". Output terminal Q is clock terminal C
Since it changes only when K rises from "L" to "H", the downshift function is still maintained. During this downshift, the output terminal Q is at "H", so the output terminal Q1 is at "L", and the input terminal D is at "L".

Then, when the downshift switch 5, which has returned to its original position, is pressed again, the clock terminal CK rises from "L" to "H", so that the output terminal Q outputs the signal "L" of the input terminal D. , cancel the downshift function.

As described above, since the output terminal Q of the control section 9 is not connected to the clock terminal CK, each time the downshift switch 5 which has returned to its original position is pressed again, the clock terminal CK changes from "L" to "L". It will change to "H". Therefore, the downshift function is repeatedly turned on and off. Other operations are similar to those in the first embodiment.

(Third Embodiment) FIG. 5 is an electric circuit diagram of a speed change control device according to a third embodiment of the present invention, and FIG. 6 is a control flowchart thereof.

As shown in the figure, the speed change control device of this embodiment is as follows:
The forward/reverse switches F, R are not connected to the control circuit 6, and are only connected to the clear terminal CLR of the control section 9 via the capacitor C1. The other configurations are the same as those of the second embodiment.

In the above configuration, the two-speed gear switch 2
The circuit power is turned on only by turning on nd. Then, the clear terminal CLR rises with a delay due to the capacitor C1,
The control section 9 is cleared. Then, when the downshift switch 5 is turned on, the gear is shifted down, but from then on, the signal at the clock terminal CK changes every time the downshift switch 5 is pressed until the 2nd speed switch 2nd is turned off. The downshift function turns on and off.

Further, even if the forward/reverse switches F and R are switched, the state does not change because no signal is input. in this case,
The downshift function is performed regardless of the position of the forward/reverse lever, so the downshift function is performed even when driving in reverse.

Therefore, when driving forward, turning on the downshift function, scooping up dirt with the bucket, and then reversing, the driver has to decide whether or not to activate the downshift function depending on the condition of the road surface. should decide. For example, if the road surface is flat, pressing the downshift switch 5 to move backward will drive the vehicle in second gear. Furthermore, when the road surface slopes forward, if the vehicle moves backward without pressing the downshift switch 5, the vehicle can travel in first gear and obtain a large driving force.

(Fourth Embodiment) FIG. 7 is an electric circuit diagram of a speed change control device according to a fourth embodiment of the present invention, and FIG. 8 is a control flowchart thereof.

In the speed change control device of this embodiment, a parallel connection of a capacitor C1 and a capacitor C2 is connected to a clear terminal CLR of a control section 9 via a first relay contact 13, and an output terminal Q of a control section 9 is connected to a parallel connection of a capacitor C1 and a capacitor C2. is the second relay contact 14
It is also connected to the clock terminal CK via the terminal CK, and the other configurations are the same as those of the first embodiment.

In the above configuration, the downshift function is performed in the same manner as in the first embodiment, but the subsequent functions are different. That is, even if the downshift switch 5 is pressed while the forward switch F is currently on, the signal from the output terminal Q will not be output to the clock terminal CK, as in the first embodiment.
, the downshift function continues. To cancel this, switch to reverse switch R, the clear terminal becomes "L", and this is canceled.

In order to perform the downshift function in this reverse state, the downshift switch 5 can be pressed. However, during this backward movement, the second relay contact 14 is switched and the output terminal Q of the control section 9 is not connected to the clock terminal CK, so the downshift function repeats on and off every time the downshift switch 5 is pressed. .

That is, in this embodiment, when moving forward, once the downshift switch 5 is pressed, the downshift function continues even if the switch 5 is pressed again. Even if the downshift switch 5 is operated, the downshift function is not canceled.

When going backwards, depending on the condition of the road surface, for example, if the vehicle is moving forward, the downshift switch 5 may be pressed to activate the downshift function, or if the road is flat, the downshift function may be activated by moving backwards. All you have to do is cancel the function and then drive without pressing the downshift switch 5.

(Fifth Embodiment) FIG. 9 is an electric circuit diagram of a speed change control device according to a fifth embodiment of the present invention, and FIG. 10 is a control flowchart thereof.

As shown in the figure, the speed change control device of this embodiment is as follows:
A capacitor C1 is connected to the clear terminal CLR of the control section 9 via the first relay contact 13, and the output terminal Q of the control section 9 is connected to the clear terminal CLR of the control section 9.
and output terminal Q1 are connected in parallel to clock terminal CK via second relay contact 14. The other configurations are the same as those of the fourth embodiment.

[0049] In the above structure, the downshift function is possible only in the forward movement state, and this point differs from the above-described embodiments. In this downshift state, downshift switch 5
Even if the button is pressed, the signal from the output terminal Q is being input to the clock terminal CK, so there is no change in its status. Therefore, when moving forward, if you press downshift switch 5 once,
You can drive in 1st gear.

[0050] Also, from the forward switch F to the reverse switch R
Even if the relay coil RL2 is demagnetized and the relay contacts 13 and 14 are switched, the clear terminal CLR
The state of does not change because there is no capacitor, and therefore,
The downshift function remains unchanged. However, in this case, the signal from output terminal Q is not input to clock terminal CK,
A signal "L" from the output terminal Q1 is input. Therefore, the clock terminal CK becomes "L". Therefore, each time the downshift switch 5 is turned on, the downshift function is turned on and off.

When the forward switch F is further turned on from this state, the clear terminal CLR is set to "L" for a certain period of time by the capacitor C1, so that the downshift function is canceled.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

In the above embodiment, switching from 2nd speed to 1st speed has been explained, but switching from 3rd speed to 1st or 2nd speed, and from 4th to 3rd, 2nd speed, etc.
The present invention can also be applied to switching to a speed gear or one speed gear.

[0054]

As is clear from the above description, according to claims 1, 2, and 3 of the present invention, the shift down means not only moves the forward/reverse lever to the forward position but also moves it to the rear position. It exhibits a similar downshift function. Therefore, when working in a place where the vehicle is tilted forward or when driving force is required when going backwards, the driving force can be exerted simply by pressing the downshift switch, which is an excellent effect.

[Brief explanation of drawings]

FIG. 1 is an electrical circuit diagram of a speed change control device according to a first embodiment of the present invention.

FIG. 2 is also a control flowchart thereof.

FIG. 3 is an electrical circuit diagram of a speed change control device according to a second embodiment of the present invention.

FIG. 4 is a control flowchart of the same.

FIG. 5 is an electrical circuit diagram of a speed change control device according to a third embodiment of the present invention.

FIG. 6 is a control flowchart thereof.

FIG. 7 is an electrical circuit diagram of a speed change control device according to a fourth embodiment of the present invention.

FIG. 8 is a control flowchart of the same.

FIG. 9 is an electrical circuit diagram of a speed change control device according to a fifth embodiment of the present invention.

FIG. 10 is a control flowchart of the same.

[Explanation of symbols]

F Forward switch R Reverse switch CK Clock terminal 1, 2 Solenoid operated valve 5 Downshift switch 9 Control section

Claims (3)

[Claims] [Claim 1] Manual switching of a transmission that controls vehicle speed is performed by connecting and connecting a plurality of fluid pressure clutches, and a first electromagnetically operated valve (2) and a second electromagnetically operated valve independently actuate each fluid pressure clutch. A tractor shovel equipped with (1) is provided with a gear switch group (3) that controls the energization of each electromagnetically operated valve, and the operation of the first speed gear switch (2nd) of the switch group. state, the solenoid operated valve (1) for the second speed gear lower than that
) to turn on the downshift switch (5).
), and a control circuit (6) for controlling the electromagnetically operated valves (1, 2) based on a switching signal from the downshift switch (5), the control circuit (6) The ON signal of the first speed gear switch (2nd) and the downshift switch (5) cuts off the power to the electromagnetic operated valve (2) for the first speed gear, and the electromagnetic operated valve (2) for the second speed gear is turned off. (1), and when the downshift means is operating, the downshift switch (
5) maintaining means for maintaining the downshift state regardless of the ON signal; and when the downshifting means is operating,
The switch for the second speed gear is activated by a switching signal from one of the forward switch (F) and reverse switch (R) to the other, or a switching signal from the first speed switch (2nd) to the other speed switch. A speed change control device for a tractor shovel, comprising a release means for cutting off energization to an electromagnetically operated valve (1) for a first speed stage and energizing an electromagnetically operated valve (2) for a first speed gear. [Claim 2] Manual switching of a transmission that controls vehicle speed is performed by connecting and connecting a plurality of fluid pressure clutches, and a first electromagnetically operated valve (2) and a second electromagnetically operated valve operate each fluid pressure clutch independently. A tractor shovel equipped with (1) is provided with a gear switch group (3) that controls the energization of each electromagnetically operated valve, and the operation of the first speed gear switch (2nd) of the switch group. state, the solenoid operated valve (1) for the second speed gear lower than that
) to turn on the downshift switch (5).
), and a control circuit (6) for controlling the electromagnetically operated valves (1, 2) based on a switching signal from the downshift switch (5), the control circuit (6) The ON signal of the first speed gear switch (2nd) and the downshift switch (5) cuts off the power to the electromagnetic operated valve (2) for the first speed gear, and the electromagnetic operated valve (2) for the second speed gear is turned off. A downshift means (1) that supplies power to the downshift switch (5), a switching signal from one of the forward switch (F) and the reverse switch (R) to the other when the downshift means is in operation; The electromagnetically actuated valve for the second speed gear (2nd) is activated by the ON signal of
1), and turn off the power to the first speed gear solenoid operated valve (2).
) A speed change control device for a tractor shovel, comprising a release means for energizing. 3. Manual switching of the transmission that controls vehicle speed is performed by connecting and connecting a plurality of fluid pressure clutches, and a first electromagnetically operated valve (2) and a second electromagnetically operated valve operate each fluid pressure clutch independently. A tractor shovel equipped with (1) is provided with a gear switch group (3) that controls the energization of each electromagnetically operated valve, and the operation of the first speed gear switch (2nd) of the switch group. state, the solenoid operated valve (1) for the second speed gear lower than that
) to turn on the downshift switch (5).
), and a control circuit (6) for controlling the electromagnetically operated valves (1, 2) based on a switching signal from the downshift switch (5), the control circuit (6) The ON signal of the first speed gear switch (2nd) and the downshift switch (5) cuts off the power to the electromagnetic operated valve (2) for the first speed gear, and the electromagnetic operated valve (2) for the second speed gear is turned off. (1), and when the downshift means is operating, the downshift switch (
5) on signal or the first speed switch (2nd
) to another speed gear switch, the release means cuts off the energization to the electromagnetic operated valve (1) for the second speed gear and energizes the electromagnetic operated valve (2) for the first speed gear. A speed change control device for a tractor shovel, comprising: