JPH0721365Y2 - Towing tractor traction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a towing device for a towing tractor.

(Prior Art) Each of FIGS. 6 to 8 shows a prior art relating to the attachment / detachment of the drawbar pin in the traction device.

First, the one shown in FIG. 6 is a primitive method in which the drawbar pin 3 is simply inserted and removed by the driver himself.

In FIG. 7, the operation lever 16 and the drawbar pin 3 are connected via a mechanical link 40, and the operation lever 16 is operated so that the pin 3 can be inserted and removed.

Further, in FIG. 8, air is used as a drive source of the drawbar pin 3. That is, the drawbar pin 3 is connected to the air cylinder 41 connected to the air source, and the air is supplied to and discharged from the air cylinder 41 by opening and closing the air valve 42 by operating a switch.

(Problems to be Solved by the Invention) Each of the above-mentioned conventional techniques has the following problems. First, in the case of the one shown in FIG. 6, since the drawbar pin 3 is simply inserted, there is a possibility that the pin 3 may fly up due to a shock or the like at the time of traveling and rattling noise may be generated. Further, if the vehicle is a small-sized vehicle, the pin 3 can be inserted and removed while sitting in the driver's seat, but it cannot be operated on a large-sized vehicle, a vehicle with a cabin, or the like, and there is a trouble of getting off the vehicle.

In the case of FIG. 7, it is necessary to convert the swinging operation of the operation lever 16 into a linear motion of raising and lowering the drawbar pin 3, so that the structure of the entire mechanism is complicated depending on the size of each element, the mounting position, etc. Therefore, it may be difficult to design.

In the case of FIG. 8, an air supply source for attaching and detaching the drawbar pin 3 is required. For this reason, it is necessary that the equipment for mounting the tractor be of a type equipped with such an air source, and for example, it will be limited to the type equipped with an air servo brake.

In view of these problems, the present invention aims to solve the drawbar pin easily and reliably with a simple structure, which is a technical problem to be solved.

(Means for Solving the Problems) In order to solve the above problems, the present invention relates to a towing tractor traction device, in which a drawbar pin detachable hydraulic cylinder is abbreviated as the drawbar pin. An operating lever arranged concentrically, connecting the lower end of the piston rod of the hydraulic cylinder and the upper end of the drawbar pin, and providing the bottom side of the hydraulic cylinder at a position where it can be operated in the driver's seat of the towing tractor. It is characterized in that it is connected to an input cylinder operated by a hydraulic pipe through a hydraulic pipe, and a spring for pushing down the drawbar pin for urging the piston rod downward is accommodated on the head side of the hydraulic cylinder.

Therefore, according to the towing tractor pulling device of the present invention, when the operating lever is operated to generate the hydraulic pressure in the input cylinder, the hydraulic cylinder pushes up the piston rod of the hydraulic cylinder against the spring. And the drawbar pin is pulled out from the drawbar bracket. On the other hand, when the operating force of the operating lever is released and the hydraulic pressure of the input cylinder is erased, the piston rod of the hydraulic cylinder is pushed down by the spring and the drawbar pin is fitted into the drawbar bracket.

(Embodiment) An embodiment embodying the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, the traction devices T1 and T2 of this example are provided in front and rear portions of the vehicle body 1 of the towing tractor. Both are connected to the lever operating portion L via a hydraulic pipe P.

First, the two towing devices T1 and T2 will be described. These are drawbar brackets 2 fixed to the front and rear end faces of the vehicle body 1.
It is installed at. Both brackets 2 horizontally extend a pair of facing pieces 2a facing each other at a predetermined interval vertically. A fitting hole 4 for inserting the drawbar pin 3 is concentrically penetrated therethrough, and the drawbar pin 3 is inserted into the fitting hole 4 from above.

On the upper facing piece 2a, a cylindrical pin guide 5 for guiding the raising / lowering operation of the drawbar pin 3 is provided upright concentrically with the fitting hole 4. The pin guide 5 further has a hydraulic cylinder 6 stacked on top of it, and the two are connected by fastening the opposing flange surfaces to each other with a bottle. The hydraulic cylinder 6 has a built-in piston 7, and its piston rod 8 projects into the pin guide 5 and is pin-jointed to the upper end of the drawbar pin 3. Further, the piston rod 8 is fitted with a spacer 10 which also functions as a stopper in the hydraulic cylinder 6, and the piston 7 is fitted with the spacer 10 and fixed by a nut 11. Further, an air vent 12 is provided on the head side of the hydraulic cylinder 6 and a spring 13 is housed therein. The spring 13 urges the piston 7 downward to prevent the drawbar pin 3 from jumping up.

A reservoir tank 14 and a check valve 15 are provided on the lever operation portion L side of the hydraulic pipe P, and are branched on the downstream side thereof to the bottom side of the hydraulic cylinders 6 of the front and rear traction devices T1 and T2. It is connected. Further, solenoid valves V1 and V2 corresponding to both traction devices T1 and T2 are interposed in the branched portion, and an oil passage communicating with each traction device T1 and T2 is selectively selected according to the operating direction of the operating lever 16. Open and close.

Next, the lever operation unit L will be described. A rod 17 is connected to an operation end of an operation lever 16 provided near the driver's seat, and the rod 17 is connected to a hydraulic pipe P via a link 18.
It is connected to an input cylinder 19 incorporated therein.

Details of the operating lever 16 will be described with reference to FIGS. 2 to 4. The operation lever 16 is composed of an upper lever 16a and a lower lever 16b connected to the rod 17, and the lower lever 1
6b is attached to a bracket 21 fixed to the machine base 20 through a pin 22 so as to be swingable around the pin 22. Also, a clevis 23 is fixed to the upper end of the lower lever 16b, and an upper lever 16a is swingably attached thereto via a pin 24. However, this pin 24 is the lower lever
It is arranged orthogonal to the pin 22 that supports 16b, so that the operating direction of the upper lever 16a alone is
It will be orthogonal to the operation direction of (the entire operation lever 16).

Also, a pair of switch brackets 25 are attached to one of the opposing pieces of the clevis 23 so as to project in the left and right directions shown in FIG. 2, and limit switches SW1 and SW2 are fixed to the upper lever 16a, respectively. ing. Both limit switches SW1 and SW2 are corresponding solenoid valves V
It is for turning on and off 1, V2, and the upper lever
When the rocking operation of 16a is performed, it can be operated by the plates 26 attached to both left and right sides of the lever 16a.

In the case of FIG. 2, the left limit switch SW2 corresponds to the rear traction device T2, and the right limit switch SW1 corresponds to the front traction device T1.

A mechanism for holding the drawbar pin 3 in a pulled-up state is provided between the clevis 23 and the upper lever 16a (see FIG. 4).

A ball 29 is interposed between the clevis 23 and the upper lever 16a, and a locking recess 31 for engaging the ball 29 is formed on the upper lever 16a side. The clevis 23 side has a hole diameter larger than that of the ball 29.
A spring guide 27 for accommodating a spring 30 for pressing 29 to the upper lever 16a side is screwed in, and a plug 28 is screwed into an opening on the front side of the spring guide 27 for covering.

Since the locking recess 31 is formed in a mountain shape in horizontal cross section, when the lever 16a is released at a position close to the operation end of the upper lever 16a, the spring force of the spring 30 causes a neutral position. Can be automatically returned to.

The upper end side of the upper lever 16a is inserted into a lever guide 32 for guiding the operation of the lever 16a (see FIG. 4). The lever guide 32 is formed with a guide groove 33 having a C-shape as a whole. In the figure, N indicates a neutral position, and R and F open an oil passage for opening both solenoid valves V1 and V2. Positions F ′ and R ′ are operating positions with respect to the input cylinder 19, and F ″ and R ″ are lock positions for holding the drawbar pin 3 in the pulled-up state. However, at the lock position, the solenoid valves V1 and V2 are kept in the ON state.

Reference numeral 34 indicates a connecting portion such as a trailer.

The traction device of this example is configured as described above.
For example, when a trailer or the like is to be connected to the rear traction device T2, the upper lever 16a is first oscillated to the right in FIG. Accordingly, the upper lever 16a is guided along the guide groove 33 of the lever guide 32, and in the clevis 23, the ball 29 is relatively displaced leftward while being pushed along the slope of the locking recess 31. , Is pushed into the spring guide 27 against the spring 30. And the upper lever
When 16a is operated to the oil passage opening position R of the guide groove 33, the plate 26 turns on the limit switch SW2, so that the solenoid valve V2 opens the oil passage.

Then, the entire operation lever 16 is swung to move the upper lever 16a to the operating position R '. In this case, since the limit switch SW2 remains on, the oil passage is held open. When the rod 17 is pulled according to the operation of the operation lever 16 as a whole, the input cylinder 19 is operated via the link 18. Then the input cylinder
The hydraulic pressure generated in 19 acts on the hydraulic cylinder P through the hydraulic pipe P and the solenoid valve V2. For this reason, the spring 13
The piston 7 is lifted up against this, and as a result, the drawbar pin 3 is pulled up via the rod 8.

When the upper lever 16a is further displaced to the lock position R ″, the ball 29 is returned to the neutral position side, so that the spring 29
The spring force of 30 keeps the upper lever 16a in this position even if the operator releases his hand. As described above, in the lock position, the solenoid valve V2 continues to be in the ON state, and the input cylinder 19 is locked.
The pulling state of is maintained. Thus, in this state, the connecting portion 34 such as a trailer can be fitted between the opposing pieces 2a of the drawbar bracket 2.

After that, when lowering the drawbar pin 3, the upper lever 16a may be returned in the reverse order of the above. That is,
When the oil cylinder opening position R is returned from the lock position R ″ and the operating position R ′, the input cylinder 19 returns to the original position, but since the solenoid valve V2 keeps the oil passage open, the pressure in the hydraulic cylinder 6 is reduced. The oil is drained, so the piston 13 is lowered by the spring 13 and the drawbar pin 3
Goes down. Then, the connection between the pin 3 and the connecting portion 34 is completed. In this connection state, the spring 13 in the hydraulic cylinder 6 resists the pull-out of the drawbar pin 3 due to the impact during traveling.

When the front traction device T1 is used, the upper operation lever 16a may be operated in the opposite direction to the above.

(Effect of the Invention) As described in detail above, according to the present invention, hydraulic pressure is generated by the operating lever, and the hydraulic cylinder for attaching and detaching the drawbar is operated by the hydraulic pressure so that the drawbar pin can be attached and detached. Therefore, a special power laying hydraulic power source for operating the hydraulic cylinder is not required, so that it can be widely applied regardless of the model. Also, since the drawbar pin is attached and detached by hydraulic pressure, remote operability is improved, and a reliable and small operation force is required. Moreover, the drawbar pin is biased in the inserting direction by the spring, that is, downward. With this configuration, it is possible to prevent rattling of the drawbar pin during traveling, and to prevent accidental popping out of the drawbar bracket to reliably maintain the inserted state.

[Brief description of drawings]

FIG. 1 is a system diagram of a traction device of this example, FIG. 2 is a front view of an operating lever, FIG. 3 is a side view of the same, FIG. 4 is a plan sectional view showing the periphery of a locking recess, and FIG. FIG. 6 is a plan view showing a lever guide, FIGS. 6 and 7 are front views showing a towing tractor equipped with a conventional traction device, and FIG. 8 is an explanatory view showing another conventional traction device. 3 ... Drawbar pin 6 ... Hydraulic cylinder 16 ... Operating lever 19 ... Input cylinder T1, T2 ... Traction device L ... Lever operating part P ... Hydraulic piping

Claims (1)

[Scope of utility model registration request] 1. A hydraulic cylinder for attaching and detaching a drawbar pin is arranged substantially concentrically with the drawbar pin on a drawbar bracket into which the drawbar pin is inserted and removed.
An input cylinder and a hydraulic pressure, which connect the lower end of the piston rod of the hydraulic cylinder and the upper end of the drawbar pin, and operate the bottom side of the hydraulic cylinder by an operating lever provided at a position operable in the driver's seat of the towing tractor. A towing device for a towing tractor, which is connected via a pipe and further accommodates a spring for pushing down a drawbar pin that biases a piston rod downward on the head side of the hydraulic cylinder.