JPS643728Y2 - - 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 trailer 1 can be attached and detached. Further, 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. Because 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 Publication No. 21526 and Japanese Patent Publication No. 49-41282, 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 5.

``Problem to be solved by the invention'' However, the former of the above, disclosed in Utility Model Publication No. 41-21526, has a structure in which hydraulic oil is directly pushed by pressurized air, and only the same hydraulic pressure as the air pressure can be obtained. If the trailer 1 is directly supported by the hydraulic pressure, there is a problem that if the trailer 1 is heavy, it cannot support the load.

In addition, the latter, published in Japanese Patent Publication No. 49-41282,
Efforts have been made such as using a device (booster) that integrates two pistons with different areas, applying air pressure to the larger piston, and pushing the hydraulic oil with the smaller piston, but the amount of air used is , which is extremely disadvantageous when using pressurized air for braking.Also, theoretically speaking,
In practical terms, there is also the problem that it cannot support the load of a large trailer fully loaded with cargo. Furthermore, the legs of the latter are designed to descend and touch the ground with almost no resistance due to air pressure (hydraulic pressure) and their own weight, so if the legs are lowered by operating a switching valve, etc., they will fall straight down. It is dangerous because it descends suddenly at such a speed. To avoid this danger, it is possible to put a restriction in the piping to create resistance to the flow of air or oil.
As the structure becomes more complex, the flow of air and oil becomes poorer, and other aspects are adversely affected. Furthermore, since only one of the pistons of the hydraulic cylinder has a structure in which oil can enter, a large oil tank is required, and there is also the problem that it is difficult to store the system compactly.

"Means for Solving the Problem" This invention consists of a storage section attached to the body of a trailer, a leg body inserted into the storage section so as to be able to slide up and down, and a leg body installed inside the storage section. A hydraulic cylinder that moves the oil up and down with respect to the storage part via a cylinder rod installed at the bottom of the piston, an oil tank that holds oil to be sent to this hydraulic cylinder, and an air valve. an air supply source that sends the oil in the tank to the upper cylinder chamber where the piston in the hydraulic cylinder has a large pressure receiving area; and an air supply source that sends the oil in the oil tank to the upper cylinder chamber that is operated by the air pressure sent from the air supply source. an air pump press-fitted into the hydraulic cylinder, a relief pipe connecting the oil tank to a lower cylinder chamber having a small pressure-receiving area of the piston in the hydraulic cylinder, and a relief pipe having a relief valve and communicating the upper cylinder chamber to the oil tank; The above-mentioned conventional problems are solved by providing a spring that is connected to the storage section and the leg and 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. Inside 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. has been done. Further, a spring 17s for biasing the piston 17m upward is provided below the piston 17m in the air cylinder 17k, 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 the piston 7m is lowered to a position lower than the exhaust hole 17h, the air in the inner upper part of the air cylinder 17k is exhausted from the exhaust hole 17h, so that 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, and drains the oil in the oil tank 16 between the check valve 16c and the check valve 16.
The oil is sucked into the communication path 16b between the cylinders d and 16b, 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 opening 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 reducing 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 configuration will be described.

When raising the trailer when attaching or detaching the trailer and tractor, use the rapid-forwarding air valve 23.
Open the air supply source 21 to the pipes 20, 24,
Air pressure is applied to the oil tank 16 through the oil tank 16 through the oil tank 16 to transfer the oil to the communication path 1.
6b to the upper cylinder chamber 12A. 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 the shock that occurs due to sudden grounding can be eliminated, failures caused by 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
Since the air pump 17 can be lowered with an excessive amount of air, excessive air consumption of the air pump 17 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 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. Incidentally, 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 that the hydraulic cylinder 12 is not affected.

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 to the
c is supplied to the lower cylinder chamber 12B.
If the release of the relief valve 17a is continued here, the spring B
The force causes the legs 10 to rise away from the ground and be stored in the storage section 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.

``Effect of the invention'' As explained above, this invention consists of a storage section attached to the body of the trailer, a leg body inserted vertically and slidably into the storage section, and a leg body installed inside the storage section. It is equipped with a hydraulic cylinder that moves the body up and down relative to the storage part via a cylinder rod installed at the bottom of the piston, an oil tank that holds oil to be sent to this hydraulic cylinder, and an air valve that applies air pressure to the oil tank. an air supply source that sends oil in the oil tank to an upper cylinder chamber with a large pressure-receiving area of the piston in the hydraulic cylinder, and is operated by air pressure sent from the air supply source;
An air pump for pressurizing the oil in the oil tank into the upper cylinder chamber, a relief pipe connecting the oil tank to the lower cylinder chamber where the pressure receiving area of the piston in the hydraulic cylinder is small, and a relief valve are provided. It consists of a relief pipe that communicates with the upper cylinder chamber, and a spring that is connected to the housing section and the leg body and urges the leg body upward, so that when the air valve is opened, air pressure is applied to the oil tank. By applying this, it is possible to quickly send oil at low pressure to the hydraulic cylinder, and therefore the legs can be lowered in rapid traverse to touch the ground, reducing the time required to change the trailer and tractor. . Moreover, at this time, the oil returning from the lower cylinder chamber through the relief pipe into the oil tank and the spring act as resistance to prevent the leg from rapidly descending (falling), so there is little danger and high safety is achieved.

In addition, when the legs touch the ground, the air pump is activated to send oil in the oil tank little by little at high pressure to the upper cylinder chamber of the hydraulic cylinder, and the hydraulic cylinder is extended, so it can be fully loaded. Even large trailers can be easily lifted.

Therefore, if you operate the air pump after fast forwarding until the legs touch the ground as described above,
Since the operation of the air pump can be suppressed to the necessary minimum, the amount of pressurized air used can be reduced, which is very advantageous when using pressurized air for control purposes.

Furthermore, since the legs are always biased upward by springs, even if some kind of failure occurs in the pneumatic or hydraulic system, the legs will not move while the trailer is running. It will not descend and cause an unexpected accident.

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, and the piston When the engine is raised, the oil in the oil tank is stored in the lower cylinder chamber, so the oil tank can have a small capacity and the whole can be stored compactly.

[Brief explanation of drawings]

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, a leg body 10 that is vertically slidably inserted into this housing part 11, and a leg body 10 that is provided in the housing part 11 and is housed through a cylinder rod 13 that is provided at the lower part of the piston 12a. A hydraulic cylinder 12 that moves up and down with respect to the section 11, and this hydraulic cylinder 1
2, and an air valve 23. Air pressure is applied to the oil tank 16 to direct the oil in the oil tank 16 to the upper cylinder chamber 12A, which has a large pressure receiving area of the piston 12a in the hydraulic cylinder 12. Air supply source 21
and an air pump 17 which is operated by air pressure sent from the air supply source 21 and pressurizes the oil in the oil tank 16 into the upper cylinder chamber 12A.
, a relief pipe 17c connecting the oil tank 16 to the lower cylinder chamber 12B, which has a small pressure receiving area of the piston 12a in the hydraulic cylinder 12, and a relief valve 1.
7a, and a relief pipe 17b that communicates the upper cylinder chamber 12A with the oil tank 16, and a spring B that is connected to the storage section 11 and the leg body 10 and pulls the leg body 10 upward. Auxiliary leg device in etc.