JP3049429U - Low floor type hydraulic jack - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a low-floor hydraulic jack used for replacing a shoe of a bridge girder, fine adjustment of machine installation, lifting at a very small gap, etc., a heavy object to be lifted against a mounted object. Even if the vehicle is inclined, it can be lifted properly and the overall height is made as low as possible. SOLUTION: A base 2 placed on an object A to be mounted, a cylinder 3 provided on the upper side thereof so as to be tiltable, and a piston which is provided to be able to ascend and descend to be able to abut a heavy object B to be lifted. 4, an oil chamber 5 formed between the cylinder 3 and the piston 4 for raising the piston 4 by the supply of pressurized oil, And a safety nut 6 that can be combined.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an improvement of a low-floor hydraulic jack used for, for example, replacing a shoe of a bridge girder, fine-tuning the installation of a machine, or lifting a small gap.

[0002]

[Prior art]

 Conventionally, as this kind of low floor type hydraulic jack, for example, one described in Japanese Utility Model Publication No. 7-9902 is known. This basically consists of a cylinder mounted on the object to be mounted, a ram provided on the cylinder so as to be able to move up and down, and raised by the supply of pressurized liquid, and a heavy object mounted on the ram and And a safety nut screwed to the outer periphery of the cylinder so as to be able to move up and down so as to be able to contact the head.

[0003]

[Problems to be solved by the invention]

 However, if the object to be lifted is not parallel to the object to be placed and is not inclined, it cannot be lifted properly and the safety nut must be brought into contact with the head. Therefore, there was a problem that the total height was increased by the thickness. The present invention has been made in view of the above-mentioned problems, and has been made to solve the problem. The subject of the present invention is to properly lift a heavy object even if the heavy object is inclined with respect to the object. An object of the present invention is to provide a low-floor hydraulic jack that can be weighed and the overall height can be minimized.

[0004]

[Means for Solving the Problems]

 The low-floor hydraulic jack according to the present invention basically includes a base mounted on an object to be mounted, a cylinder provided on the base so as to be tiltable, and a cylinder mounted on the cylinder so as to be able to move up and down. A piston capable of contacting a heavy object, a liquid chamber formed between the cylinder and the piston to raise the piston by supply of pressurized liquid, and a liftable screw screwed to the outer periphery of the cylinder to form a lifted heavy object. The feature is that it is composed of a safety nut that can be fitted and

[0005] The low-floor hydraulic jack is inserted between the object to be mounted and the object to be lifted, and the base is mounted on the object to be mounted. When the pressurized liquid is supplied to the liquid chamber, the piston is raised with respect to the cylinder, and the object to be lifted is lifted against the object to be mounted. When the object to be lifted is not parallel to the object to be mounted but is inclined, the cylinder is tilted relative to the base in accordance with the inclination angle, and the object to be lifted is properly lifted. When the lifted object has been lifted by the specified amount, the safety nut is screwed into contact with the lifted object. At this time, the safety nut is provided on the cylinder that can be tilted with respect to the base, so that even if the object to be lifted is tilted, it can be properly engaged.

Preferably, a convex spherical surface is formed on the upper surface of the base, and a concave spherical surface suitable for the convex spherical surface is formed on the lower surface of the cylinder. By doing so, the bottom wall of the cylinder can be bent upward, which contributes to further lowering the overall height while maintaining the strength of the bottom wall of the cylinder and the stroke of the piston at predetermined values. .

It is preferable that a plating layer is formed on the inner periphery of the cylinder, and a metal layer having a lower hardness than the plating layer is formed on the outer periphery of the piston. By doing so, the liquid-tight function can be improved, and the galling phenomenon of the piston with respect to the cylinder is reduced, so that smooth sliding is performed.

[0008] A lift line indicating the maximum lift position is preferably formed on the outer periphery of the piston. In this way, excessive rise of the piston can be visually confirmed, and trouble due to this can be prevented.

[0009] It is preferable that a recess is formed in the lower surface at the center of the piston. In this way, the piston can reduce the weight of the hydraulic jack as a whole and contribute to further reducing the overall height.

[0010]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing a cross section of the right half of the low floor type hydraulic jack according to the present invention. FIG. 2 is a plan view of FIG. 1 showing only half.

The main part of the low-floor hydraulic jack 1 is composed of a base 2, a cylinder 3, a piston 4, a liquid chamber 5, and a safety nut 6.

The base 2 is mounted on the object A to be mounted. In this example, the base 2 has a disk shape, has a flat lower surface and a convex spherical surface 7 formed on the upper surface, and has a central portion. Is formed with a stepped hole 8.

The cylinder 3 is provided so as to be tiltable above the base 2. In this example, the cylinder 3 has a bottomed cylindrical shape whose upper side is opened by a side wall 9 and a bottom wall 10. Is a concave spherical surface 11 conforming to the convex spherical surface 7 of the base 2, a raised portion 12 in the middle of the upper surface of the bottom wall 10, a plating (hard chrome plating) layer 13 on the inner periphery, and an upper half on the outer periphery. Male screws 14 are respectively formed. The cylinder 3 is attached to the base 2 in a tiltable and non-separable manner by means of a washer 15 and a bolt 16 which are inserted and hooked into the stepped holes 8 of the base 2.

The piston 4 is provided in the cylinder 3 so as to be able to ascend and descend so as to be able to abut the object B to be lifted. In this example, the piston 4 has a disk shape and its outer periphery is harder than the plating layer 13 of the cylinder 3. (A copper alloy deposition metal) layer 17 having a small diameter, a circumferential groove 18 in the lower part of the outer circumference, a lift line 19 indicating the maximum head position in the middle of the outer circumference, and a raised line 12 of the cylinder 3 on the lower surface in the center. The recess 20 which does not interfere is formed with three concentric non-slip grooves 21 on the upper surface. An O-ring 22 and a backup ring 23 for sealing with the cylinder 3 are inserted into the circumferential groove 18.

The liquid chamber 5 is formed between the cylinder 3 and the piston 4 and raises the piston 4 by supplying a pressurized liquid. In this example, the liquid chamber 5 is provided between the cylinder 3 and the lower surface of the piston 4. Is formed. The cylinder 3 is provided with a port 24 communicating with the liquid chamber 5, into which a coupling 25 connected to a liquid pressure supply source (not shown) is screwed.

The safety nut 6 is screwed to the outer periphery of the cylinder 3 so as to be able to ascend and descend so as to be able to abut the object B to be lifted. In this example, a female screw 26 that fits the male screw 14 of the cylinder 3 is provided. It comprises an annular nut 27 formed and four handles 28 implanted in the shape of a plane cross.

Next, the operation will be described based on such a configuration. The low-floor hydraulic jack 1 is inserted between the object A and the object B to be lifted, and the lower surface of the base 2 is placed on the upper surface of the object A. When the pressurized liquid from the liquid pressure supply source is supplied to the liquid chamber 5 via the coupling 25 and the port 24, the piston 4 is raised with respect to the cylinder 3 as shown by a chain line in FIG. A to be lifted against A is lifted. When the lifted object B is not parallel to the object A but is inclined, the cylinder 3 is inclined with respect to the base 2 by the convex spherical surface 7 of the base 2 and the concave spherical surface 11 of the cylinder 3. The lifted object B is properly lifted. Once the lifted heavy object B has been lifted by a certain amount, the handle 28 of the safety nut 6 is gripped and turned to screw the safety nut 6 against the cylinder 3 to lift the upper surface thereof. It is brought into contact with the lower surface of heavy material B. At this time, since the safety nut 6 is provided on the cylinder 3 which can be tilted with respect to the base 2, even if the object B to be lifted is inclined, it can be properly engaged.

The upper surface of the base 2 has a convex spherical surface 7, the lower surface of the bottom wall 10 of the cylinder 3 has a concave spherical surface 11 adapted to the convex spherical surface 7 of the base 2, and the upper surface of the bottom wall 10 of the cylinder 3 has a raised portion. 12 are formed at the center lower surface of the piston 4 with depressions 20 which do not interfere with the raised portion 12 of the cylinder 3, so that the strength of the bottom wall 10 of the cylinder 3 and the stroke of the piston 4 are maintained at predetermined values. The overall height can be reduced further.

In the above example, the base 2 and the cylinder 3 have the convex sphere 7 formed on the base 2 and the concave sphere 11 formed on the cylinder 3. However, the present invention is not limited to this. Although the plating layer 13 is formed on the cylinder 3 in the above-described example, the present invention is not limited to this. For example, the cylinder 3 may be omitted or may be other than hard chrome plating. In the above example, the metal layer 17 is formed on the piston 4, but the present invention is not limited to this. For example, the metal layer 17 may be omitted or a material other than the copper alloy weld metal may be used. The piston 4 forms the lift line 19 in the previous example, but is not limited to this, and may be omitted, for example. In the above example, the piston 4 has the recess 20 formed therein. However, the present invention is not limited to this. For example, the recess 20 may be omitted.

[0020]

[Effect of the invention]

 As described above, according to the present invention, the following excellent effects can be obtained. (1) A base to be placed on an object to be placed, a cylinder provided on the upper side of the base so as to be tiltable, a piston provided to be movable up and down and capable of abutting against a heavy object to be lifted, and a cylinder. And a safety nut formed between the piston and the piston to raise the piston by the supply of pressurized liquid, and a safety nut screwed to the outer periphery of the cylinder so as to be able to move up and down and to be able to abut the object to be lifted. Even if the object to be lifted is inclined with respect to the object to be mounted, it can be properly lifted and the overall height can be made as low as possible. (2) Since the safety nut is provided on the cylinder that can tilt with respect to the base, the safety nut can be brought into contact with the heavy load even if the heavy load is inclined with respect to the load. And secure the safety.

[Brief description of the drawings]

FIG. 1 is a cross-sectional front view of the right half of a low-floor hydraulic jack according to the present invention.

FIG. 2 is a plan view of FIG. 1 showing only half.

[Explanation of symbols]

1. Low floor hydraulic jack, 2. Base, 3. Cylinder,
4 piston, 5 liquid chamber, 6 safety nut, 7 convex spherical surface, 8 stepped hole, 9 side wall, 10 bottom wall, 11 concave curved surface, 12 raised portion, 13 plating layer, 14 ... male screw, 1
5 ... Washer, 16 ... Bolt, 17 ... Filled metal layer, 18 ... Circumferential groove, 19 ... Length line, 20 ... Hump, 21 ... Slip groove, 22 ...
O-ring, 23 ... backup ring, 24 ... port,
25: coupling, 26: female screw, 27: nut, 2
8: handle, A: mounted object, B: heavy object to be lifted.

Claims (5)

[Utility model registration claims] 1. A base mounted on an object to be mounted, a cylinder provided on the base so as to be tiltable, a piston provided up and down on the cylinder and capable of abutting against a heavy object to be lifted, and a cylinder. A liquid chamber formed between the piston and the piston to raise the piston by the supply of pressurized liquid, and a safety nut screwed to the outer periphery of the cylinder so as to be able to move up and down so as to be able to abut a heavy object to be lifted. A low-floor hydraulic jack characterized by the following: 2. The low-floor hydraulic jack according to claim 1, wherein a convex spherical surface is formed on an upper surface of the base, and a concave spherical surface adapted to the convex spherical surface is formed on a lower surface of the cylinder. 3. The low-priced metal plate according to claim 1, wherein a plating layer is formed on an inner periphery of the cylinder, and a metal layer having a hardness smaller than that of the plating layer is formed on an outer periphery of the piston. Floor type hydraulic jack. 4. The low-floor hydraulic jack according to claim 1, wherein a lift line indicating a maximum lift position is formed on an outer periphery of the piston. 5. The low-floor hydraulic jack according to claim 1, wherein a recess is formed in a central lower surface of the piston.