JP6313732B2 - Rolling machine - Google Patents

Description

  The present invention relates to a rolling machine for compacting a road surface, and more particularly to a rolling machine such as a vibrating roller vehicle equipped with an HST (hydrostatic power transmission).

  In the brake apparatus for an HST vehicle disclosed in Patent Document 1, a brake hydraulic circuit is connected to a brake of a drive mechanism that uses an HST motor as a drive source, and the hydraulic oil supplied to the brake hydraulic circuit is cut off to break the brake. Can be activated. In this brake device, the HST control hydraulic circuit communicates with the downstream of the brake valve that opens and closes the brake hydraulic circuit.

  When the brake hydraulic circuit is shut off by the brake valve and the brake is operated, the brake hydraulic circuit and the tank are brought into communication. As a result, the hydraulic circuit for HST control is communicated with the tank via the hydraulic circuit for brake, the hydraulic pressure of the hydraulic oil flowing through the hydraulic circuit for HST control is released, and cannot be driven by HST unless the operation of the brake is released. Thus, the brake device can perform safe braking, and increases the reliability of the brake device.

Japanese Utility Model Publication No. 6-23859

  The brake device disclosed in Patent Document 1 can also be applied to a negative parking brake that receives the charge pressure as a release pressure and releases the braking of the HST motor. However, piping for connecting the hydraulic circuit for brake and the hydraulic circuit for HST control, and an electromagnetic valve for blocking and connecting the piping are required. The addition of piping, electromagnetic valves, and the like in such a hydraulic circuit has a problem that the cost of the HST circuit including the parking brake circuit and the occupied space increase.

  The present invention has been made in view of such a problem, and the object of the present invention is to reduce the cost and space-saving of the HST circuit including the parking brake circuit, while maintaining the safety of braking by the parking brake and An object of the present invention is to provide a rolling machine that can increase reliability.

  In order to achieve the above object, the rolling machine of the present invention is connected to an HST circuit in which an HST pump and an HST motor are connected in a closed circuit by an oil path, and hydraulic oil to be charged pressure is supplied, A negative parking brake that receives the charge pressure as a release pressure to release the braking of the HST motor, and a multi-stage transmission that is connected to the HST motor and receives the charge pressure to switch the speed stage between a high speed stage and a low speed stage. The HST circuit has high speed stage holding means for electrically switching and holding the speed stage of the multi-stage transmission to the high speed stage when the parking brake is operated and the HST motor is braked.

  Preferably, the HST circuit includes a parking brake electromagnetic valve that switches between supply and cutoff of charge pressure to the parking brake, and a parking brake circuit to which the parking brake electromagnetic valve is electrically connected, and charging to the multi-stage transmission. Including a shift solenoid valve that switches the speed stage to a high speed stage and a low speed stage by switching between supply and cutoff of pressure, and further includes a shift circuit to which the shift solenoid valve is electrically connected, The power line electrically connects the parking brake circuit and the speed change circuit.

  Preferably, the parking brake circuit further includes a parking brake switch that activates the parking brake by turning on to brake the HST motor, and deactivates the parking brake to release the braking of the HST motor by turning off. When the parking brake switch is off, the valve is supplied with charge pressure to release the brake of the HST motor, while when the parking brake switch is on, the charge pressure to the parking brake is shut off and HST Brakes the motor.

  Preferably, the speed change circuit further includes a battery for supplying power to the speed change circuit, the speed change solenoid valve switches the speed stage to a low speed stage when the power supply from the battery is interrupted, and the high speed stage holding means includes a parking brake. When the HST motor is braked by operation, when the speed stage is at the low speed stage, the speed stage is electrically switched to the high speed stage by supplying power from the parking brake circuit to the shifting solenoid valve of the transmission circuit via the power line. Switch and hold.

  Preferably, the speed change circuit further includes a speed change fuse that cuts off the power supply from the battery due to an overcurrent flowing in the speed change circuit, and the high speed stage holding means changes the speed when the parking brake is operated and the HST motor is braked. Even when the power supply from the battery is cut off by cutting the fuse for power, the speed stage is electrically switched to the high speed stage by supplying power from the parking brake circuit to the solenoid valve for speed change via the power line. Hold.

  Preferably, when the parking brake switch is on, the parking contact is turned on when the movable contact is in contact with the open contact, and when the parking brake switch is off, the parking contact is turned off while the movable contact remains closed. The parking brake solenoid valve is energized when the movable contact of the parking brake relay is off, and is opened by the energization to supply charge pressure to the parking brake so that the HST motor On the other hand, when the movable contact of the parking brake relay is turned on, the parking brake relay is de-energized, and the valve is closed by the de-energization, whereby the charge pressure to the parking brake is cut off and the HST motor is braked.

Preferably, the power line is connected to the open contact side of the parking brake relay in the parking brake circuit and the shifting electromagnetic valve in the transmission circuit.
Preferably, the HST circuit includes delay means for delaying switching of the speed stage to the high speed stage by the high speed stage holding means when the parking brake is operated and the HST motor is braked.
Preferably, the delay means is a timer that is provided in the power line and delays power feeding from the parking brake circuit to the shift solenoid valve of the shift circuit.

  Preferably, the delay means is an orifice provided in an oil passage for hydraulic oil connected to the multi-stage transmission from the shift solenoid valve.

  According to the compaction machine of the present invention, the safety and reliability of braking by the parking brake can be improved while realizing low cost and space saving of the HST circuit including the parking brake circuit.

It is a side view of the vibration roller which is an example of the compaction machine which concerns on embodiment of this invention. FIG. 2 is a hydraulic circuit diagram showing a part of the HST circuit according to the first embodiment of the present invention provided in the vibration roller of FIG. 1. FIG. 3 is an electric circuit diagram showing a parking brake circuit and a transmission circuit provided in the HST circuit of FIG. 2. It is a flowchart which shows the flow of the high speed stage maintenance performed with the parking brake circuit and transmission circuit of FIG. It is an electric circuit diagram showing a parking brake circuit and a transmission circuit according to a modification of the present invention. It is a hydraulic circuit diagram which shows the HST circuit which concerns on another modification of this invention. 7 is a flowchart showing a flow of high-speed stage holding performed in FIG. 5 or FIG. 6.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the rolling compactor according to the present embodiment is a vibration roller vehicle 1 that performs a paving work, for example. The vibration roller vehicle 1 is schematically composed of a front vehicle body 4 provided with a front roller 2 and a rear vehicle 8 provided with a rear roller 6. The front vehicle body 4 and the rear vehicle body 8 are articulated so as to be bent in the horizontal direction via a center pin 10, and the vibration roller vehicle 1 bends the front vehicle body 4 and the rear vehicle body 8 to each other. By doing so, the vehicle can be turned.

  The front rolling roller 2 is composed of a metal drum having a length substantially corresponding to the vehicle width, and is rotatably supported by a pair of left and right support arms 12 extending downward from the front vehicle body 4. On the other hand, the rear rolling roller 6 includes a pair of two rubber tires 6a and 6a and a pair of left and right rubber tires 6a, and is composed of a total of four rubber tires 6a. Yes.

  An operation console 18 having a steering 16 is installed at a front position on the rear vehicle body 8, and a seat 20 is installed on the rear side of the operation console 18. Various operation switches such as a parking brake switch 24 for operating a parking brake 22 described later are disposed on the operation table 18. An operator sitting on the seat 20 drives the vibration roller vehicle 1 by operating the steering 16 and an accelerator lever and a forward / reverse lever (not shown), and the pavement work is performed by the front roller 2 and the rear roller 6. Roll the road surface.

FIG. 2 shows only the hydraulic circuit on the front roller 2 side in the HST circuit 26 as a representative. Regarding the features of the present embodiment, the hydraulic circuit on the rear rolling roller 6 side has almost the same configuration as the hydraulic circuit on the front rolling roller 2 side, so the description of the hydraulic circuit on the rear rolling roller 6 side is omitted. To do.
The front roller 2 is driven by being transmitted with the power of the drive plate 29. The drive plate 29 is driven by transmitting the power of the HST motor 28 of the HST circuit 26.

The HST circuit 26 is connected in a closed circuit together with the HST pump 32 in an oil passage that is a pipe through which hydraulic oil flows, and an HST pump 32 that is a bi-tilting variable displacement hydraulic pump driven by the engine 30. The above-described HST motor 28 which is a traveling hydraulic motor.
The HST circuit 26 is provided with a charge circuit 34 that supplies hydraulic oil to the low pressure side of the oil passage. The charge circuit 34 has a charge pump 36, and the charge pump 36 supplies the hydraulic oil boosted to the charge pressure from the hydraulic oil tank 38 to the HST circuit 26.

A parking brake 22 and a multi-stage transmission 40 are connected to the HST motor 28.
The parking brake 22 is a negative type brake that releases the braking of the HST motor 28 by receiving the charge pressure of the hydraulic oil boosted by the charge pump 36 by the operation of the parking brake switch 24 as a release pressure. Although not shown, the parking brake 22 is a friction plate (inner teeth) that rotates integrally with the output shaft of the HST motor 28, a friction plate (outer teeth) that slides or moves away from the friction plate (inner teeth), A piston integral with the friction plate (external teeth), a disc spring that presses the friction plate (external teeth) against the friction plate (internal teeth) via the piston, and a release pressure that presses the piston against the disc spring It consists of a release pressure chamber for introduction.

  In the parking brake 22, when the release pressure is introduced into the release pressure chamber, the piston moves against the disc spring, and accordingly, the friction plate (outer teeth) is separated from the friction plate (inner teeth). The braking of the motor 28 is released. If the pressure in the release pressure chamber does not reach the release pressure, the friction plate (external teeth) is pressed against the friction plate (internal teeth) via the piston by the disc spring, and the HST motor 28 is braked. In addition, a parking brake electromagnetic valve 42 is connected to the discharge side of the charge pump 36 in the HST pump 32, and the supply and cutoff of the charge pressure to the parking brake 22 are switched by the parking brake electromagnetic valve 42.

  On the other hand, the multi-stage transmission 40 receives the charge pressure of the hydraulic oil boosted by the charge pump 36 and switches the speed stage between a high speed stage and a low speed stage. A shift switching valve 44 is connected to the discharge side of the charge pump 36. The shift switching valve 44 is provided in the HST motor 28, and the supply of the charge pressure to the multi-stage transmission 40 is switched off and off by a shift electromagnetic valve 46 provided separately on the HST pump 32 side. The speed stage is switched between a high speed stage and a low speed stage.

Here, in this embodiment, when the parking brake switch 24 is operated and the parking brake 22 is operated and the HST motor 28 is braked, the speed stage of the multi-stage transmission 40 is electrically switched to the high speed stage. The HST circuit 26 is provided with high-speed holding means for holding.
Specifically, as shown in FIG. 3, the HST circuit 26 includes a parking brake circuit 48 to which a parking brake electromagnetic valve 42 is electrically connected, and a transmission circuit 50 to which a shifting electromagnetic valve 46 is electrically connected. It has. The parking brake circuit 48 and the speed change circuit 50 are connected by a power line (high speed stage holding means) 51 (described later) and electrically connected to achieve high speed stage holding in the multi-stage transmission 40.

  Hereinafter, with reference to FIGS. 3 and 4, the high speed stage holding of the speed stage of the multi-stage transmission 40 performed by the HST circuit 26 will be described in detail. The parking brake circuit 48 is formed by a closed circuit connection of a parking brake solenoid valve 42, a parking brake switch 24, a parking brake relay 52, and the like. The parking brake circuit 48 is supplied with power from the battery 60, and the power supply from the battery 60 is interrupted by the parking brake fuse 56 due to an overcurrent flowing through the parking brake circuit 48.

  When the parking brake switch 24 is turned on, the parking brake 22 is operated to brake the HST motor 28. On the other hand, when the parking brake switch 24 is turned off, the parking brake 22 is deactivated and the braking of the HST motor 28 is released. When the parking brake switch 24 is on, the parking brake relay 52 is turned on when the movable contact 52a contacts the open contact 52c. On the other hand, when the parking brake switch 24 is off, the parking brake relay 52 is turned off while the movable contact 52a remains the closed contact 52b.

  The parking brake electromagnetic valve 42 is energized when the movable contact 52a of the parking brake relay 52 is off, and is opened by the energization to supply charge pressure to the parking brake 22 to brake the HST motor 28. Is released. On the other hand, the parking brake solenoid valve 42 is de-energized when the movable contact 52a of the parking brake relay 52 is on, and is closed by the de-energization, whereby the charge pressure to the parking brake 22 is shut off and the HST motor 28 is closed. Brake.

The transmission circuit 50 is formed by connecting a transmission electromagnetic valve 46 on the HST pump 32 side, a transmission switch 58, and the like. The speed change circuit 50 is supplied with power from the battery 60, and the power supply from the battery 60 is interrupted by the speed change fuse 62 due to an overcurrent flowing through the speed change circuit 50. The shift solenoid valve 46 switches the speed stage of the multi-stage transmission 40 to the low speed stage when the power supply from the battery 60 is cut off due to the cutting of the shift fuse 62 or the like.
The power line 51 is connected to the open contact 52 c side of the parking brake relay 52 in the parking brake circuit 48 and to the shift electromagnetic valve 46 side in the transmission circuit 50.

As shown in FIG. 4, it is first determined whether or not the parking brake switch (P / B / SW) 24 is activated (ON) (step S11). When the P / B / SW 24 is on (Yes), the process proceeds to step S12. When the P / B / SW 24 is not on (No), the process proceeds to step S11 again.
Next, in step S12, the parking brake relay (P / B relay) 52 is excited (turned off), and the process proceeds to steps S13 and S14.

  In step S13, the parking brake solenoid valve (P / B solenoid valve) 42 is deenergized and the process proceeds to step S15. In step S15, the parking brake (P / B) 22 is operated to brake the HST motor 28, and this flow is returned. On the other hand, in step S14, the power line 51 is energized as the parking brake solenoid valve 42 is de-energized, and the process proceeds to step S16.

In step S16, when the parking brake 22 is actuated and the HST motor 28 is braked, power is supplied from the parking brake circuit 48 to the shifting electromagnetic valve 46 of the transmission circuit 50 via the power line 51 when the speed stage is the low speed stage. By doing so, the speed stage of the multi-stage transmission 40 is electrically switched from the low speed stage to the high speed stage, and this flow is returned.
Further, when the parking brake 22 is activated and the HST motor 28 is braked, the power supply from the battery 60 is cut off by cutting the gearshift fuse 62, and the speed stage of the multi-stage transmission 40 is changed to the low speed stage by the interruption. Even if the switching is performed, the speed stage of the multi-stage transmission 40 is electrically switched to the high speed stage and held by supplying power from the parking brake circuit 48 to the electromagnetic valve 46 for the speed change circuit 50 via the power line 51. .

  As described above, in the vibration roller vehicle 1 of the present embodiment, the HST circuit 26 includes the power line 51 as a high speed stage holding unit for the speed stage of the multi-stage transmission 40. Thus, when the parking brake 22 is activated and the HST motor 28 is braking, when the speed stage of the multi-stage transmission 40 is the low speed stage, the speed stage is electrically switched to the high speed stage and held. When the speed stage is a high speed stage, the speed stage can be held as it is. Therefore, it is not necessary to separately provide a solenoid valve or the like for shutting off or communicating the piping that is the oil passage in the HST circuit 26. That is, the above-described high-speed stage holding means can be realized by adding only one power line 51, that is, one harness, to the electric circuit constituting the parking brake circuit 48 and the transmission circuit 50 without modifying the hydraulic circuit. .

  Further, by holding the speed stage of the multi-stage transmission 40 at a high speed while the parking brake 22 is operating, the risk of the vibration roller vehicle 1 moving on a slope or the like can be surely eliminated, and the parking brake 22 The braking safety and reliability can be improved. Specifically, on an extremely steep slope, when the operator accidentally operates the forward / reverse lever while the parking brake 22 is operating, due to the high torque of the low speed stage and the vehicle weight of the vibration roller vehicle 1, The starting force of the vibration roller vehicle 1 is greater than the braking force of the parking brake 22, and the risk of the vibration roller vehicle 1 moving cannot be eliminated.

However, by providing the high speed stage holding means, it is possible to reliably prevent such unintended start of the vibration roller vehicle 1. Therefore, the safety and reliability of braking by the parking brake 22 can be improved while realizing low cost and space saving of the HST circuit 26 including the parking brake circuit 48.
In addition, by supplying power from the parking brake circuit 48 to the shifting solenoid valve 46 of the transmission circuit 50 via the power line 51, power supply from the battery 60 is cut off by cutting the shifting fuse 62, and the transmission circuit 50 is in a non-powered state. Even when the speed stage becomes a low speed stage, the speed stage of the multi-stage transmission 40 can be reliably switched to the high speed stage and held.

  Further, the power line 51 is connected to the open contact 52 c side of the parking brake relay 52 in the parking brake circuit 48 and the shifting electromagnetic valve 46 in the transmission circuit 50. As a result, even if the parking brake relay 52 does not move due to sticking or the like, the parking brake electromagnetic valve 42 is opened (turned on) by energization, that is, although the parking brake switch 24 is on. In the state where the braking of the HST motor 28 is released and the vibration roller vehicle 1 can travel, it is possible to prevent a situation in which the speed stage is changed from the low speed stage to the high speed stage and suddenly accelerates against the operator's will. it can.

Although the description of the embodiment of the present invention has been completed above, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention.
For example, as shown in FIG. 5, when the parking brake 22 is actuated and the HST motor 28 is braked, the power line of the HST circuit 26 is used as delay means for delaying the switching of the speed stage to the high speed stage by the high speed stage holding means. 51 may be provided with a timer 64. The timer 64 delays power supply from the parking brake circuit 48 to the shifting electromagnetic valve 46 of the shifting circuit 50.

  As another example of the delay means, as shown in FIG. 6, an orifice 68 is connected to an oil passage 66 that connects a shift electromagnetic valve 46 on the HST pump 32 side and a shift switching valve 44 on the HST motor 28 side. May be provided. Since the flow path of the oil path 66 is narrowed by the orifice 68, the flow of hydraulic oil between the speed change switching valve 44 and the speed change electromagnetic valve 46 is delayed.

  As shown in FIG. 7, by providing step S17 of such a delay means between steps S14 and S16 which are step routes on the speed stage switching side, the speed stage is changed after the parking brake 22 is reliably operated. Switch to high speed stage. Therefore, it is possible to prevent braking by the parking brake 22 after the speed stage is switched to the high speed stage for a moment. Therefore, the state in which the vibration roller vehicle 1 is accelerated and moved immediately before braking is eliminated, and the uncomfortable feeling of the operator's drive feeling can be surely wiped off.

  In the above embodiment, the hydraulic circuit on the front roller 2 side in the HST circuit 26 is shown as a representative in FIG. 2, and the high-pressure stage holding according to the present invention has been described. However, as described above, with respect to the features of this embodiment, the hydraulic circuit on the rear rolling roller 6 side has almost the same configuration as the hydraulic circuit on the front rolling roller 2 side, and the high-pressure stage holding of the present invention is the rear rolling roller. Of course, it is also performed when the pressure roller 6 is braked.

  In the above embodiment, the present invention has been embodied by the vibration roller vehicle 1. However, the rolling machine to be applied is not limited to this, and Macadam with both front and rear wheels being iron rings (rolling wheels). The present invention may be applied to a vehicle such as a roller or a tire roller having front and rear wheels as rubber tires.

1 Vibration roller vehicle (rolling machine)
DESCRIPTION OF SYMBOLS 22 Parking brake 24 Parking brake switch 26 HST circuit 28 HST motor 32 HST pump 40 Multistage transmission 42 Parking brake solenoid valve 44 Shifting switching valve 46 Shifting solenoid valve 48 Parking brake circuit 50 Shifting circuit 51 Power line (High-speed stage holding) means)
52 Parking brake relay 52a Movable contact 52b Closed contact 52c Open contact 60 Battery 62 Shifting fuse 64 Timer (delay means)
66 Oil passage 68 Orifice (delay means)

Claims (10)

An HST circuit in which an HST pump and an HST motor are connected in a closed circuit by an oil passage, and hydraulic oil serving as a charge pressure is supplied;
A negative parking brake connected to the HST motor and receiving the charge pressure as a release pressure to release the braking of the HST motor;
A multi-stage transmission connected to the HST motor and receiving the charge pressure to switch the speed stage between a high speed stage and a low speed stage;
The HST circuit includes high-speed stage holding means for electrically switching and holding the speed stage of the multi-stage transmission to the high speed stage when the parking brake is operated and the HST motor is braked. Pressure machine. The HST circuit
A parking brake circuit that includes a parking brake solenoid valve that switches between supply and cutoff of the charge pressure to the parking brake, and the parking brake solenoid valve is electrically connected;
A shift that includes a shift solenoid valve that switches the speed stage to the high speed stage and the low speed stage by switching between supply and cutoff of the charge pressure to the multi-stage transmission, and the shift solenoid valve is electrically connected And further comprising a circuit,
The compaction machine according to claim 1, wherein the high-speed stage holding means is a power line that electrically connects the parking brake circuit and the transmission circuit. The parking brake circuit further includes a parking brake switch that activates the parking brake when on to brake the HST motor, and deactivates the parking brake and deactivates braking of the HST motor when off.
The solenoid valve for parking brake releases the braking of the HST motor by supplying the charge pressure to the parking brake when the parking brake switch is off, while the parking brake switch is on. The rolling machine according to claim 2, wherein the charge pressure to the parking brake is cut off to brake the HST motor. The transmission circuit further includes a battery that supplies power to the transmission circuit,
The shift solenoid valve switches the speed stage to the low speed stage when power supply from the battery is interrupted,
The high speed stage holding means is configured such that when the parking brake is operated and the HST motor is braked, the speed shift of the transmission circuit is performed from the parking brake circuit via the power line when the speed stage is the low speed stage. The compaction machine according to claim 3, wherein the speed stage is electrically switched to the high speed stage and held by supplying power to the electromagnetic valve for operation. The speed change circuit further includes a speed change fuse that interrupts power supply from the battery due to an overcurrent flowing through the speed change circuit,
When the parking brake is operated and the HST motor is braked, the high-speed stage holding means is provided with the parking brake circuit even when power supply from the battery is cut off by cutting of the shift fuse. 5. The compaction machine according to claim 4, wherein the speed stage is electrically switched to the high speed stage by supplying power from the power line to the solenoid valve for speed change of the speed change circuit via the power line. When the parking brake switch is on, the parking contact is turned on when the movable contact comes into contact with the open contact, while the movable contact remains closed when the parking brake switch is off. It further includes a parking brake relay,
The electromagnetic valve for parking brake is energized when the movable contact of the parking brake relay is off, and is opened by the energization to supply the charge pressure to the parking brake to brake the HST motor. On the other hand, the parking brake relay is de-energized when the movable contact is on, and is closed by the de-energization to cut off the charge pressure to the parking brake and brake the HST motor. Item 6. The rolling machine according to Item 4 or 5.   The pressure rolling machine according to claim 6, wherein the power line is connected to the open contact side of the parking brake relay in the parking brake circuit and to the shifting electromagnetic valve in the transmission circuit.   The said HST circuit has a delay means which delays switching the said speed stage to the said high speed stage by the said high speed stage holding means, when the said parking brake act | operates and the said HST motor is braked. Rolling machine.   9. The compaction machine according to claim 8, wherein the delay unit is a timer that is provided in the power line and delays power feeding from the parking brake circuit to the electromagnetic valve for shifting of the transmission circuit.   The pressure reduction machine according to claim 8, wherein the delay means is an orifice provided in the oil passage of the hydraulic oil connected to the multi-stage transmission from the shift solenoid valve.

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