JPH0143965Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention relates to an auxiliary leg device that is installed on a trailer or the like to support the vehicle body of the trailer.

``Prior Art'' As shown in FIG. 1, a trailer 1 is connected to a tractor 2 through a coupler 3 provided at the rear of the vehicle body of the tractor 2 to be towed and transports cargo 4. Auxiliary leg devices 6 are provided on both sides of the vehicle body of the trailer 1, and the legs 5 are extended and retracted to raise and lower the trailer 1, and the coupler 3
and trailer 1 can be attached and detached. Furthermore, when the trailer 1 is removed from the tractor 2 and placed on the road surface, the legs 5 can be lowered to support the body of the trailer 1.

By the way, if a hydraulic cylinder is used for the auxiliary leg device 6 and a hydraulic pump provided on the tractor 2 is connected to the hydraulic cylinder to move the leg body 5 up and down, the tractor 2 and the tractor 1 can be connected or disconnected. Since it is necessary to connect and separate hydraulic pipes, there are inconveniences such as air getting into the hydraulic system and oil leakage when connecting and separating hydraulic pipes. As seen in Japanese Patent No. 126110, a technique has been proposed in which air is pressurized into an oil tank and hydraulic oil is sent to a hydraulic cylinder to extend and retract the legs.

``Problems to be solved by the invention'' However, the device disclosed in Utility Model Application Publication No. 53-126110 has a structure in which the hydraulic oil is directly pressed by pressurized air, and the structure is such that only the same oil pressure as the air pressure can be obtained. If the trailer is directly supported by the hydraulic pressure, there is a problem that if the trailer is heavy, it will not be able to support the load.

This invention was developed in view of the above circumstances, and allows the legs to be lowered safely and quickly to touch the ground, and after touching down, applies a large force to the legs to raise and lower the trailer. To provide an auxiliary leg device that requires less space, is compact and fits well, and can be installed on a trailer.

``Means for solving the problem'' This idea is designed to solve the above-mentioned conventional problems.
A storage section attached to the body of the trailer, an oil tank installed in the storage section, a hydraulic cylinder fixed to the bottom of the oil tank with a cylinder rod facing up and down, and connected to the lower end of the cylinder rod. a piston attached to the upper end of the cylinder rod that divides the interior of the hydraulic cylinder into an upper cylinder chamber and a lower cylinder chamber; a communication path provided between the cylinders and communicating the oil tank and the upper cylinder chamber; a check valve incorporated in the communication path to allow fluid to flow from the oil tank side to the upper cylinder chamber side; A relief pipe that communicates the oil tank with the lower cylinder chamber in the inner cylinder, a relief pipe that is equipped with a relief valve and communicates the upper cylinder chamber with the oil tank, and a relief pipe that communicates with the communication path between the check valves and the oil tank. An air pump having a connecting pipe attached to a tank, a piston rod slidably inserted into the connecting pipe, and a piston at the upper end of the piston rod, and connected to an air supply and reciprocating the piston rod by the air pressure. , a pipe communicating an air supply source to the upper part of the oil tank, an air valve incorporated in the pipe to switch communication between the oil tank and the air supply source and communication between the oil tank and the atmosphere, and connected to the leg body. It consists of a spring that pulls the leg upward.

Embodiment FIGS. 2 to 4 show an embodiment of this invention, in which reference numeral 10 denotes legs provided on both sides in the width direction of the trailer on the side closer to the tractor. This leg body 10 is constructed by attaching a plate-shaped foot part 10b to the lower end of a cylindrical leg part 10a, and is attached to a cylindrical storage part 11 fixed to each lower part of both sides in the vehicle width direction of the trailer facing downward. , the leg portion 10a is slidably inserted so that the leg portion 10a can be freely moved up and down. An oil tank 16 is attached to the inner upper part of the storage section 11, an air pump 17 is attached above the oil tank 16, and a downwardly facing hydraulic cylinder 12 is attached below the oil tank 16. In the hydraulic cylinder 12,
A piston 12a is provided, and the inside of the hydraulic cylinder 12 is connected to an upper cylinder chamber 12A by the piston 12a.
and a lower cylinder chamber 12B, and a cylinder rod 13 passing through the lower end wall of the hydraulic cylinder 12 is attached to the lower surface of the piston 12a. A communication path 16b is formed in the bottom wall of the oil tank 16 to connect the oil tank 16 and the upper cylinder chamber 12A of the hydraulic cylinder 12.
A check valve 16 that allows fluid to flow from the to the upper cylinder chamber 12A side and prevents fluid from flowing to the opposite side.
c and 16d are installed spaced apart from each other.

The communication path 16b between the check valve 16c and the check valve 16d is connected to the air pump 17 through a connecting pipe 17d. This air pump 17
An air cylinder 17k equipped with a piston 17m operated by air pressure is provided inside the cylinder 17, and a piston rod 17j reciprocated by the piston 17m is slidably inserted into the connecting pipe 17d. ing. Furthermore, a piston 1 is located below the piston 17m in the air cylinder 17k.
A spring 17s is provided to bias the air cylinder 7m upward, and an exhaust hole 17h is formed in the side wall of the air cylinder 17k. Then, the piston 17m is lowered by the required air pressure against the biasing force of the spring 17s, and the piston 17m
When m falls to a position lower than the exhaust hole 17h, the air at the inner upper part of the air cylinder 17k flows into the exhaust hole 1.
Since the air is exhausted from 7h, the piston 17m is raised by the biasing force of the spring 17s. The above-mentioned vertical movement of the piston 17m causes the piston rod 17j to reciprocate, thereby draining the oil in the oil tank 16 through the check valves 16c and 16d.
The oil is sucked into the communication passage 16b between the two cylinders, and the oil is sequentially and intermittently sent to the upper cylinder chamber 12A at high pressure. Further, the upper cylinder chamber 12A is connected to the oil tank 16 by a relief pipe 17b incorporating a relief valve 17a, and the lower cylinder chamber 12B is connected to the oil tank 16 by a relief pipe 17c.

On the other hand, a cylindrical rubber bushing D for buffering is attached to the lower end of the cylinder rod 13 extending below the hydraulic cylinder 12, and a cylindrical mounting member E is inserted into this rubber bushing D. E
A ring-shaped connecting member F is fitted to each of the lengthwise ends of the cylinder rod 13. is connected to the leg portion 10a. That is, as the cylinder rod 13 moves up and down, the legs 10 move up and down along the storage section 11. The rubber bush D is used to reduce the impact transmitted from the leg 10 to the cylinder rod 13 and the load applied to the cylinder rod 13 when the leg 10 is tilted.

In addition, round holes 14 and 1 are provided on both sides of the lower part of the storage portion 11.
4 is drilled, and the round holes 15 of the mounting member E on both sides of the leg body 10 are aligned with the round holes 14, 14 when the leg body 10 finishes extending. It can be inserted into the hole 14 and the round hole 15 to prevent the leg body 10 from moving up and down. In addition, a spring B is provided on the side of the storage portion 11.
However, one end thereof is connected to a protrusion C that protrudes into the storage section 11.
The other end is attached to the lower surface of the leg body 10, respectively, and is provided parallel to the leg portion 10a of the leg body 10.

By the way, the upper part of the air cylinder 17k in the air pump 17 is connected to the air valve 1 for driving the air pump via the air pump control pipe 18.
The air valve 19 for driving the air pump is also connected to an air supply source 21 via an air supply pipe 20. On the other hand, the oil tank 16 is connected to a fast-forwarding air valve 23 via a fast-forwarding pipe 22, and this fast-forwarding air valve 23 is connected to a pipe 24.
It is connected to the air supply pipe 20 via. Further, the fast-forwarding air valve 23 is connected to an air chamber 27 via an air chamber pipe 26, and the air chamber 27 is open to the atmosphere. This air chamber 27
This is a well-known type that functions as an air distribution box when air is released to the atmosphere from the air chamber pipe 26, and exhibits a silencing effect. Furthermore, the air pump 17 includes a silencer 28 and a relief valve 17a.
A pressure reduction pot 29 for opening and closing is attached, and the relief valve 17a can be opened and closed by operating this pot 29.

Next, the operation of the auxiliary leg device having the above structure will be explained.

When raising the trailer when attaching or detaching the trailer and the tractor, open the fast-forwarding air valve 23 and supply air from the air supply source 21 to the pipes 20, 2.
Air pressure is applied to the oil tank 16 through the oil tank 4 and 22, and the oil in the oil tank 16 is rapidly sent to the upper cylinder chamber 12A through the communication path 16b. By this operation, the cylinder rod 13 moves rapidly with a small cylinder output, and the leg body 10 housed in the housing part 11 is lowered along the side wall 11 of the housing part 11.

When air pressure is applied to the oil tank 16 here, pressure is applied to both the inlet on the oil tank 16 side of the communication path 16b and the inlet on the oil tank 16 side of the relief pipe 17c, but the area on the upper surface of the piston 12a that receives the oil pressure is larger than the area of the lower surface of the piston 12a that receives the hydraulic pressure (the area of the upper surface of the piston 12a that receives the pressure is larger by the cross-sectional area of the cylinder rod 13), so the piston 12a resists the biasing force of the spring B. It descends due to the pressure difference between the top and bottom and its own weight. At this time, the oil in the lower cylinder chamber 12B is removed from the relief pipe 17.
C, returns to the oil tank 16 through spring B, acts as a resistance together with spring B, prevents the piston 12a from rapidly descending, and makes the lowering speed of the leg 10 at an appropriate speed. Since it is possible to eliminate the shock that occurs due to sudden grounding, damage and failure of equipment due to the shock can be prevented.

When the lower surface of the leg 10 touches the ground, the fast-forwarding air valve 23 is switched to close the pipe 24, and the air pump driving air valve 19 is opened to send air to the air pump 17. A piston 17m provided in a cylinder 17k reciprocates up and down, and the connecting pipe 1
The piston rod 17j within the piston rod 7d reciprocates to intermittently send oil in the oil tank 16 at high pressure little by little to the upper cylinder chamber 12A of the hydraulic cylinder 12. By this operation, the cylinder rod 13 pushes the leg body 10 which is in contact with the ground with a large cylinder output, and raises the vehicle body of the trailer. Also at this time, the oil in the lower cylinder chamber 12B is returned to the oil tank 16 through the relief pipe 17c. Therefore, the oil tank 16 may have a small capacity. Note that if the cylinder rod 13 is rapidly moved by applying air pressure directly to the air tank 16 until the leg 10 touches the ground as described above, the cylinder rod 13 will be lowered from the beginning using the air pump 17. Since it can be lowered with a smaller amount of air than when
7. Excessive air consumption is prevented.

When the trailer body has finished rising, the pins A are inserted into the round holes 14 and 15 as shown in FIG. 4 to prevent the vertical movement of the leg body 10 and the air valve 19 for driving the air pump is closed. The load is supported by the storage section 11 and the legs 10. Note that even if the leg body 10 in contact with the ground is inclined to some extent due to unevenness of the ground, the rubber bush D absorbs the inclination, so no load is applied to the hydraulic cylinder 12.

If you want to lower the trailer a little from this state and connect it to the tractor, insert the pin A into the round holes 14 and 1.
5 and release the relief valve 1 using the pressure reducing pot 29.
Open 7a. Through this operation, the trailer descends due to its own weight and the biasing force of the spring B and rides on the tractor's coupler, but at this time, the piston 12a rises, so the oil in the upper cylinder chamber 12A passes through the relief pipe 17b. As the oil in the oil tank 16 returns to the oil tank 16, the oil in the oil tank 16 escapes from the pipe 17c.
The lower cylinder chamber 12B is supplied through the cylinder chamber 12B. If the relief valve 17a continues to be released, the force of the spring B causes the leg 10 to rise away from the ground and be stored in the storage portion 11. When the leg body 10 has finished rising, the relief valve 17a is closed. Note that the air sent into the oil tank 16 is supplied to the pipes 22 and 26 and the air chamber 2.
7 to the atmosphere.

As described above, the tractor can be connected using the auxiliary legs.

``Effects of the invention'' As explained above, this invention opens the air valve and applies air pressure to the oil in the oil tank from the top of the oil tank, thereby rapidly sending oil to the hydraulic cylinder at low pressure. You can quickly lower your body and touch the ground. Moreover, at this time,
The oil that returns from the lower cylinder chamber to the oil tank through the relief pipe and the spring that urges the legs upwards act as resistance to prevent the legs from dropping rapidly, allowing the legs to be moved safely and quickly. Can lower the body.

Next, when the legs touch the ground, the air pump is activated to reciprocate the piston rod up and down, and the oil in the oil tank is intermittently supplied to the communication passage, and the upper cylinder chamber of the hydraulic cylinder is intermittently supplied with high pressure. Since the cylinder rod and legs can be lowered with great force by feeding small amounts at a time, even heavy trailers can be lifted easily.

That is, according to the device of this invention, the air pump can be activated to apply a strong force to the legs after the legs are fast forwarded until they touch the ground as described above, thereby reducing the time required for the legs to descend. This reduces the time needed to replace trailers and tractors, and at the same time reduces air pump operation to the minimum necessary.
The amount of pressurized air used can be reduced, which is very advantageous when compressed air is used for controlling trailers, etc.

In addition, the oil tank, hydraulic cylinder, legs, air pump, and other equipment for raising and lowering the auxiliary legs are stored in the storage compartment attached to the trailer body, so the whole thing fits compactly and can be easily installed on the trailer. can. Moreover, the hydraulic cylinder is provided with an upper cylinder chamber and a lower cylinder chamber, both cylinder chambers communicate with an oil tank, and when the piston descends, the oil in the lower cylinder chamber is replenished into the oil tank.
When the piston moves up, the oil in the oil tank is stored in the lower cylinder chamber, so the oil tank may have a small capacity.
The whole can be stored compactly.

Furthermore, since the legs are always urged upward by springs, even if there is some kind of failure in the pressure or hydraulic system, the legs will not move while the trailer is running. It will not descend and cause unexpected accidents.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a conventional general auxiliary leg device attached to a trailer, Fig. 2 is a configuration diagram of the auxiliary leg device according to the present invention, and Fig. 3 shows the auxiliary leg device according to the present invention. FIG. 4 is a partial sectional view showing a state in which the pin is inserted into the round hole when the leg is extended. DESCRIPTION OF SYMBOLS 1...Trailer, 10...Leg body, 11...Storage part, 12...Hydraulic cylinder, 12a...Piston, 12A...Upper cylinder chamber, 12B...Lower cylinder chamber, 13...Cylinder rod, 16... ...oil tank, 17...air pump, 17a...relief valve, 17b...relief pipe, 17c...relief pipe, 21...air supply source, 23...air valve, B...spring.

Claims (1)

[Scope of utility model registration request] Storage section 1 attached to the body of trailer 1
1, an oil tank 16 installed in this storage part 11, a hydraulic cylinder 12 fixed to the lower part of the oil tank 16 with the cylinder rod 13 facing in the vertical direction, and a hydraulic cylinder 12 connected to the lower end of the cylinder rod 13. a piston 12a that is attached to the upper end of the cylinder rod 13 and divides the inside of the hydraulic cylinder 12 into an upper cylinder chamber 12A and a lower cylinder chamber 12B; and a piston 12a that is provided between the oil tank 16 and the hydraulic cylinder 12. oil tank 16
and a communication path 16b that communicates with the upper cylinder chamber 12A.
The oil tank 1 is installed in the communication path 16b.
Check valves 16c and 16d that allow fluid to flow from the 6 side to the upper cylinder chamber 12A side, a relief pipe 17c that communicates the oil tank 16 with the lower cylinder chamber 12B of the hydraulic cylinder 12, and a relief valve 17a.
The oil tank 16 has an upper cylinder chamber 12A.
and the relief pipe 17b communicating with the check valve 16.
a connecting pipe 17d attached to the oil tank 16 and communicating with the communication path 16b between the check valve 16d and the check valve 16d;
It has a piston rod 17j slidably inserted into this connecting pipe 17d and a piston 17m fixed to the upper end of the piston rod 17j, and is connected to an air supply source 21 and uses the air pressure to reciprocate the piston 17m. Pump 17, pipes 22 and 24 communicating air supply source 21 to the inner upper part of oil tank 16, and pipes 22 and 24 that are incorporated into the pipes to communicate communication between oil tank 16 and air supply source 21 and communication between oil tank 16 and the atmosphere. An auxiliary leg device for a trailer or the like, comprising an air valve 23 for switching the air valve 23, and a spring B connected to the leg body 10 to pull the leg body 10 upward.