JP2532475Y2 - Transmission power take-off device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a power take-off device for a transmission in a work vehicle.

(Prior Art) As is well known, in a vehicle such as a crane truck or a mixer truck having a structure in which the output of an engine is divided into a driving drive and a work driving, a PTO (power take-off) is used. In some cases, a driving force switching mechanism called “off” is additionally provided.

That is, the above-mentioned PTO means an operation of switching a driving force in the transmission between a driving gear for the axle side and a driving gear of, for example, a working hydraulic motor, and this switching is performed by, for example, an electromagnetic valve. It may be performed using an actuator of an air cylinder.

That is, FIG. 2 shows a drive circuit for air supply of the above-described air cylinder, and in FIG.
A clutch switch B and a PTO command switch C are connected via a clutch relay A.

The above-described clutch relay A has an exciting coil A1 which is excited when the clutch switch B is turned on. When the exciting coil A1 is excited, a contact is set to a PTO described later.
The operation command switch D is switched to a terminal A2 connected thereto.

That is, the PTO operation command switch D has the input side connected to the output side of the above-mentioned PTO command switch C, and the solenoid valve E connected to the output side.

The internal connection of the PTO operation command switch D is set as shown in the figure. When the switch is turned on, a current path to the solenoid valve E is set.

Further, the solenoid valve E is capable of, for example, setting air supply / discharge to an air tank (not shown) and opening the air to the atmosphere.
When a current is supplied, air is supplied from the air tank to the air cylinder F to move the actuator in a direction in which the meshing of the gears for obtaining the working driving force can be set. Reaching the gear meshing position is detected by a limit switch (not shown), and the air cylinder F is held at that position.

When the PTO mechanism is operating, when the PTO operation command switch D is turned on, the operating state is displayed by an indicator lamp G illuminated by the switch.

(Problems to be Solved by the Invention) In the above-described PTO mechanism, when the starter switch H of the engine is turned off, the energization of the relay is released, and the current to the solenoid valve E also stops flowing. .

Therefore, for example, when the actuator of the air cylinder F is configured to automatically return to the initial position by the return spring, the air supply is stopped, and at the same time, the attitude changed so far is changed to the attitude before the change. Will change it. In addition, the indicator lamp G indicating that the PTO operation is being performed is turned off.

For this reason, when the starter switch H is turned on again, it is necessary to repeat the above-described processing to set the PTO operation, and there is a possibility that the operation may become cumbersome.

Therefore, the purpose of the present invention is to set the PTO operation again when the starter switch is turned on again even if the starter switch is turned off in the state where the PTO operation is set, in view of the problem in the conventional PTO mechanism described above. An object of the present invention is to provide a power take-off device for a transmission that eliminates such inconvenience and has good operability.

(Means for Solving the Problems) In order to achieve this object, the present invention relates to a method of dividing a driving force of a transmission into a driving gear and a working driving gear in a transmission in order to divide the driving force of the engine into driving and working. In a power take-off device for switching engagement by using an air cylinder whose position is set by an electromagnetic valve, a clutch switch connected to a starter switch of the engine via a relay, and an input side connected to a power supply via the relay, On the output side, the first is to move the actuator of the air cylinder to a switching position, which is the meshing position of the working gear.
And a PTO operation switch to which a second solenoid valve for moving the actuator of the air cylinder toward the non-switching position, which is an initial position, is connected to an excitation coil of the first solenoid valve. A first detection switch that is turned on when the actuator of the air cylinder reaches a switching position, and a current path to an excitation coil of the second solenoid valve in a normal state. A second detection switch that is turned on when the actuator of the air cylinder reaches the non-switching position; and a second detection switch that is excited when the second detection switch is turned on and floats from the ground terminal. A drive relay whose contact is switched to a terminal; and a power supply and the PTO operation switch, which are excited when the first detection switch is turned on from the normal state. A first display holding relay for setting an energizing path with the input side of the switch, a PTO operation indicator lamp connected to an energizing path between the first display holding relay and the input side of the PTO operation switch, When the contact of the drive relay is connected to a ground terminal, the first display holding relay is excited via the drive relay in conjunction with setting an energizing path between a power supply and a PTO operation indicator lamp. The power supply is directly connected to the input side of the PTO operation switch, the second detection switch is turned from the normal state to the on state, and the contact of the drive relay is switched from the ground side terminal to the floating terminal, whereby And a second display holding relay for shutting off a power supply and an input side of the PTO operation switch.

(Operation) According to the present invention, when the PTO operation is set, that is, when the actuator is displaced to the switching position, the first detection switch is turned from the normal state to the on state, and the first detection switch is turned on via the first solenoid valve to the air cylinder. Since the air supply operation is canceled and the air supply operation is not performed on the second solenoid valve side, the actuator of the air cylinder is displaced to the switching position.

Also, in this state, the first detection switch is turned from the normal state to the on state, so that the current path to the PTO operation indicator lamp is held via the first display holding relay, so that the starter is restarted. Displayed until the switch is turned on.

Further, in the PTO operation switch, when the actuator of the air cylinder is displaced to the non-switching position, the contact point is connected to the ground side, so that the PTO operation indicator lamp is provided via the second display holding relay. To maintain the current path.

(Embodiment) Hereinafter, the embodiment of the present invention will be described in detail with reference to FIG.

FIG. 1 is a circuit diagram showing a driving unit of a power take-off device for a transmission according to an embodiment of the present invention.

That is, in this embodiment, when the starter switch is turned off when the actuator of the air cylinder is displaced to the switching position that is the meshing position of the work drive gear without using the return spring in the air cylinder, It is characterized in that a structure for holding the actuator at the position is provided, and a structure for maintaining an indication that the actuator is at the switching position is provided.

In FIG. 1, a power supply 2 in a power take-off device 1 is connected to a starter switch 3, and the starter switch 3 is connected via a relay 4 to a clutch switch 5 which is turned on when performing a PTO operation. I have.

The above-described relay 4 includes a power supply terminal 4B that is connected via an exciting coil 4A that is excited when the starter switch 3 and the clutch switch 5 are turned on. The power supply terminal 4B is a PTO operation switch to be described later. 6 is connected to the input side.

That is, the PTO operation switch 6 is internally connected as shown in the figure, and the output side is connected to the first solenoid valve 7 and the second solenoid valve 8, respectively.

The above-mentioned first solenoid valve 7 and second solenoid valve 8 perform supply / exhaust control to an air cylinder 9 for switching meshing of gears inside a transmission (not shown). It is composed of a valve that can switch between the three directions of opening and closing.

The first solenoid valve 7 displaces the actuator 9A of the air cylinder 9 in a direction for switching to a position where the driving side gear and the work driving gear can engage with each other when the excitation coil 7A is energized. The second electromagnetic valve 8 is displaced in a non-switching direction in which the engagement between the driving gear and the work driving gear is released when the excitation coil 8A is energized.

On the other hand, in the vicinity of the air cylinder 9 described above, for example, first and second detection switches 10 and 11 each configured by a limit switch are disposed in order to detect the position of the actuator 9A. First detection switch 10
Is turned on when the actuator 9A reaches the switching position, and the second detection switch 11 is turned on when the actuator 9A reaches the non-switching position shown in the figure. Has become.
Therefore, the first detection switch 10 and the second detection switch 11 are maintained in their normal positions until the actuator 9A of the air cylinder 9 completely reaches the switching position or the non-switching position. Furthermore, the first
The detection switch 10 is located between the output side of the PTO operation switch 6 and the first solenoid valve 7, and sets a normal position and a terminal for setting an energization path to the first solenoid valve 7 as shown in the figure. 10A
Being connected to.

The second detection switch 11 is a PTO operation switch 6
A terminal 11A for setting an energizing path to the second solenoid valve 8 in the normal state until the actuator 9A reaches the non-switching position, between the output side of the second solenoid valve 8 and the second solenoid valve 8.
In the state after switching after reaching the switching position, the movable contact is connected to the terminal 11B as shown in FIG.

On the other hand, a first display holding relay 12 is connected to the first detection switch 10 described above, and a drive relay 13 is connected to the second detection switch 11.

That is, the first display holding relay 12 is capable of self-excitation in which the excitation coil 12A is connected to another terminal 10B of the first detection switch 10, and the power supply terminal 12B connected to the power supply. And a floating terminal 12C. In a normal position, a contact is set to a state where the contact is connected to the floating terminal 12C. One of the contacts is a PTO operation switch disposed on the instrument panel together with the PTO operation switch 6. It is connected to the power line of the indicator lamp 15.

The drive relay 13 has an exciting coil 13A connected to a terminal 11B different from the terminal 11A of the second detection switch 11, and has a ground terminal 13B and a floating terminal 13C. Is set to be connected to the ground terminal 13B. The drive relay 13 is connected to the second
Is connected to the display holding relay 14.

That is, the second display holding relay 14 is a driving relay.
The excitation coil 14A is connected to the 13 contacts. The relay 14 is configured as a normally open type relay. When the first detection switch 10 is turned on, the contact is closed to secure a power supply line to the PTO operation switch 6.

Since the present embodiment is configured as described above, when the driving force of the engine is switched from the traveling side to the working side while the starter switch 3 is turned on, the starter switch 3, the clutch switch 5, and the PTO operation switch 6 are respectively turned on, so that the exciting coil of the relay 4 is
4A is excited and the contact is connected to the power supply terminal 4B side.

Therefore, the current from the power supply is: power supply ⇒ relay 4 contact ⇒
PTO operation switch 6 ⇒ first detection switch 10 ⇒ exciting coil 7A of first solenoid valve 7 流 れ flows in the route of ground, and moves actuator 9A of air cylinder 9 toward the switching position.

At this time, since the PTO operation switch 6 is ON, the second
The second solenoid valve 8 is in a non-excited state regardless of whether the detection switch 11 is in a normal state or not, and the second solenoid valve 8 is in an air cylinder 9
In order to allow the movement of the actuator 9A, the first solenoid valve 8 is exhausted or opened to the atmosphere in accordance with the air supply. Since the movement time of the actuator 9A in the air cylinder 9 is shorter than the time until the clutch pedal is depressed and released, power is supplied to the first solenoid valve 7 by turning on the clutch switch 5. The setting is performed on the above-described route.

Also, since the PTO operation switch 6 is ON, the drive relay is activated regardless of whether the second detection switch 11 is in the normal state.
13 is not excited, and maintains a state in which the contact is connected to the ground terminal 13B.

When the actuator 9A of the air cylinder 9 reaches the switching position, the first detection switch 10 is turned on, and the exciting coil 12 of the first display holding relay 12 is turned on.
A is excited, and the contact is switched to the power supply terminal 12B side.

Also, at this time, the power supply terminal 12B of the first display holding relay 12 and the drive relay 13 form an energizing path including the second display holding relay 14, so that the second display holding relay 14 Is connected to the power supply, and the power supply circuit of the PTO operation switch 6 is formed by the self-exciting action of the relay 14.

Therefore, the current from the power supply 2 flows through the path of the power supply 2 ⇒ the power supply terminal 12B of the first display holding relay 12 ⇒ the contact of the first display holding relay 12 ⇒ the PTO operation display lamp 15 ⇒ ground, and This indicates that the force transmission path has been switched to the work drive gear.

In this display, since the first display holding relay 12 is energized, the flow of current is changed from the power supply to the power supply side terminal 12B of the first display holding relay 12 PTO operation switch 6 to the first
Detection switch 10 ⇒ exciting coil 12A of first display holding relay 12 ⇒ grounded by self-exciting action of first display holding relay 12 obtained by flowing through the path of ground.

On the other hand, if the starter switch 3 is turned off in this state, the first solenoid valve 7 is de-energized because the first detection switch 10 is turned on, and the second detection switch 10 is turned off. Since the solenoid valve 8 is set to the exhaust side or open to the atmosphere, no displacement force acts on the actuator 9A, and the actuator 9A is held at the switching position.

At this time, the above-mentioned PTO operation indicator lamp 1
Since the conduction path to 5 is set by the self-exciting action of the first display holding relay 12, the state where the PTO display lamp 15 is lit is maintained.

Therefore, when the operator attempts to turn on the starter switch 3, the operator can determine the current state of the PTO operation.

To cancel the PTO operation, the PTO operation switch 6 is turned off.

At this time, the current from the PTO operation switch 6 is cut off to the first detection switch 10 and the first display holding relay 12 is turned off, but the second display holding relay 14 → drive relay 13
A current is supplied to the PTO operation switch 6 via the movable contact of the second display holding relay 14 by a self-holding circuit of the ground side terminal 13B → ground. At this time, since the second detection switch 11 is still switched to the terminal 11A in the normal state, the current from the power supply 2 is changed from the power supply 2 to the PTO.
The operation switch 6 ⇒ the second detection switch 11 ⇒ the second solenoid valve 8 ⇒ flows in a route of ground, and the air supply of the second solenoid valve 8 is performed so as to move the actuator 9A of the air cylinder 9 toward the non-switching position. Done.

At this time, the first solenoid valve 7 is exhausted or opened to the atmosphere in accordance with the air supply of the second solenoid valve 8 to allow the movement of the actuator 9A.

Since the second display holding relay 14 functions to form an energizing path to the indicator lamp 15, the indicator lamp 15 is turned on until the actuator 9A of the air cylinder 9 reaches the non-switching position. Will be.

When the actuator 9A of the air cylinder 9 returns to the initial position, the terminal 11B of the second detection switch 11 is turned off.
, The self-holding circuit of the second display holding relay 14 is released, the current path to the indicator lamp 15 and the PTO operation switch 6 is cut off, and the actuator 9A of the air cylinder via the second solenoid valve 8 is turned on. Is stopped.

(Effects of the Invention) As described above, according to the present invention, even when the starter switch is turned off at the time of setting the PTO, the position is maintained, so that when the starter switch is turned on again,
The trouble of redoing PTO settings is eliminated.

Even if the starter switch is turned off, the PT
Since the O setting can be displayed, it is easy to confirm when the starter switch is turned on again.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a main configuration of a power take-off device according to an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a main configuration of a conventional power take-off device. 1. Power take-off device 2. Power supply 3. Starter switch 4. Relay 5. Clutch switch 6. PTO
Operation switch, 7: first solenoid valve, 8: second solenoid valve,
9 ... air cylinder, 9A ... actuator, 10 ... first detection switch, 11 ... second detection switch, 12 ... first display holding relay, 13 ... drive relay, 14 ... second display holding relay, 15… PTO operation indicator lamp.

Claims (1)

(57) [Scope of request for utility model registration] In order to divide the driving force of an engine into traveling and working, an engagement between a traveling driving gear and a working driving gear in a transmission is performed using an air cylinder whose position is set by an electromagnetic valve. In the power take-off device for switching, a clutch switch connected to a starter switch of the engine via a relay, an input side connected to a power supply via the relay, an actuator of the air cylinder on an output side, and a working gear Moving toward the switching position, which is the meshing position of
A PTO operation switch to which a solenoid valve of the type described above and a second solenoid valve for moving the actuator of the air cylinder toward a non-switching position, which is an initial position, are respectively connected; A first detection switch which is turned on when the actuator of the air cylinder reaches the switching position, and which normally communicates with the excitation coil of the second solenoid valve. A second detection switch which sets an electric circuit and is turned on when the actuator of the air cylinder reaches a non-switching position; and a second detection switch which is energized when the second detection switch is turned on and is connected to a ground side terminal. A drive relay whose contact is switched to a floating terminal; and a power supply and the PTO operation which are excited when the first detection switch is turned on from the normal state. A first display holding relay for setting an energizing path with the input side of the switch, a PTO operation indicator lamp connected to an energizing path between the first display holding relay and the input side of the PTO operation switch, When the contact of the drive relay is connected to a ground terminal, the first display holding relay is excited via the drive relay in conjunction with setting an energizing path between a power supply and a PTO operation indicator lamp. When the power supply is directly connected to the input side of the PTO operation switch, the second detection switch is turned from the normal state to the on state, and the contact of the drive relay is switched from the ground terminal to the floating terminal, whereby Power and
A power take-off device for a transmission, comprising: a second display holding relay that cuts off an input side of a PTO operation switch.