JPH0582989U - Jack post structure - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a jack post structure having a structure in which the inner post can be smoothly moved up and down with respect to the outer post, rattling of both can be reduced, and manufacturing cost can be suppressed. [Constitution] An outer post 11 which is vertically extended and attached to a side portion of a vehicle body, and which is fitted in the outer post 11 so as to be vertically movable and is also provided in the outer post 11.
The jack 10 is composed of an inner post 12 that can project downward from the inner post 12 by a predetermined length. In addition, the fitting gap between the outer post 11 and the inner post 12 in the portion where the inner post 11 overlaps with the outer post 12 when the inner post 11 projects to the maximum extent is made smaller than the other portions.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a jack post structure in a jack device that is used to extend and support a vehicle body during work in order to ensure stability during work in an aerial work vehicle or the like.

[0002]

[Prior Art]

 An example of such a jack device is shown in FIG. In this jack device, an outrigger box 57 is fixed to the body frame so as to extend in the lateral direction, and an outrigger beam 58 is fitted into the box 57 so as to be extendable and contractable. It is extended and attached. The jack 50 includes an outer post 51 fixed to the tip of the beam 58, an inner post 52 fitted vertically up and down with respect to the outer post 51, and a ground plate joined to the lower end of the inner post 52. 53 and a jack cylinder 54 that is disposed in both posts 51 and 52 to move up and down the inner post 52.

Since the basic structure of such a jack device is the same for both the conventional device and the device according to the present invention, both of them are shown in FIG. 3, and the conventional jack device has a reference numeral in parentheses. It is shown enclosed by. Further, although the jack 50 is attached to the vehicle body frame via the outrigger in the figure, the jack device may be constructed by directly attaching the jack 50 to the vehicle body frame.

When using such a jack device, the inner cylinder 52 is lowered by the jack cylinder 54 to project downward, and the ground plate 53 is grounded to the ground to support the vehicle body. Therefore, the inner post 52 is gently inserted into the outer post 51 so that it can move up and down smoothly, and a predetermined amount of fitting gap is provided between the posts 51 and 52. Here, the outer post 51 is attached by welding to the tip of the outrigger beam 58, and as shown in FIG. 5, welding distortion easily occurs. Therefore, the fitting gap is set to be large enough to allow the inner post to be smoothly moved up and down even when there is such welding distortion.

[0005]

[Problems to be solved by the device]

 As described above, this fitting gap is necessary to smoothly move up and down the inner post 52. However, the larger this fitting gap, the greater the rattling of the inner post 52 with respect to the outer post 51, and as shown in FIG. As shown in (), when the inner post 52 is projected downward to support the vehicle body, this backlash causes the inner post 52 to sway, which tends to cause unstable support of the vehicle body. It should be noted that, by increasing the manufacturing accuracy of both posts and reducing this fitting gap, or by providing a mechanism that adjusts the fitting gap between both posts, rattling of the inner post can be reduced. There is a problem that the manufacturing cost increases.

The present invention has been made in view of such a problem, and is configured such that the inner post can be smoothly moved up and down with respect to the outer post, the rattling of the both can be reduced, and the manufacturing cost can be suppressed. The purpose of the present invention is to provide a jack post structure.

[0007]

[Means for Solving the Problems]

 In order to achieve such an object, in the present invention, an outer post that extends vertically and is mounted on a side portion of a vehicle body, and an outer post that is vertically movably fitted in the outer post and is a predetermined length downward from the outer post. The jack post structure is composed of an inner post that can project, and the fitting gap between the outer post and the inner post in the part where they overlap each other when the inner post projects downward from the outer post to the maximum extent. It is configured to be smaller than the part. As a method of reducing the fitting gap in the portion where the inner posts overlap each other in the protruding state, there are a method of squeezing the outer post in this portion and a method of thickening the inner post in this portion.

[0008]

【Example】

 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows an aerial work vehicle 1 having a jack post structure according to the present invention. This aerial work vehicle 1 is configured such that a boom 3 which is extendable and retractable is mounted on a vehicle body 2, and a work table 4 is attached to the tip of the boom 3. At the time of work, the boom 3 is controlled to move up and down and extend and retract, the work table 4 is moved to a desired high place, and the work on the work table 4 is performed by a worker on the work table 4.

In order to firmly and stably support the vehicle body 2 during such work at a high place, outrigger jacks 10 are provided at four locations on the side of the vehicle body 2. The basic structure of each jack 10 is the same as that of the conventional jack 50, and as shown in FIG. 3, the tip of the outrigger beam 8 which is laterally extendably fitted into the outrigger box 7 fixed to the vehicle body frame or the like. A jack 10 is attached to each of the. Each of the jacks 10 includes an outer post 11 which is vertically extended and fixed to the tip of the outrigger beam 8, an inner post 12 which is vertically inserted into the outer post 11, and a lower end of the inner post 12. And a jack cylinder 14 disposed in both posts 11 and 12 for raising and lowering the inner post 12.

The structure of the jack 10 is shown in detail in FIG. 1. As shown, the lower end 11 a of the outer post 11 is drawn inward. As a result, the inner dimension of the outer post 11 is larger than the outer dimension of the inner post 12 above the lower end 11a, and the fitting gap of the inner post 12 with respect to the outer post 11 is relatively large. In, the inner dimension of the outer post 11 is slightly larger than the outer dimension of the inner post 12, and the fitting gap in this portion is extremely small.

Therefore, in the portion where the fitting gap is small, the rattling of the inner post 12 with respect to the outer post 11 is restricted, and the rattling of the inner post 12 is suppressed. Further, such a portion where the fitting gap becomes small is only provided at the lower end portion 11a of the outer post 11, and when the outer post 11 is welded to the outrigger beam 8, the outer post 11 is distorted as illustrated. Even in this case, the inner post 12 can be smoothly inserted into the outer post 11 and can be smoothly moved up and down.

It is to be noted that FIG. 1B shows a state in which the inner post 12 is projected downward as much as possible. As can be seen from this figure, a portion where both posts 11 and 12 overlap in this state. In, the lower end 11a of the outer post 11 is drawn. For this reason, rattling of the inner stroke 12 can be suppressed within the entire lifting stroke range of the inner post 12, and stable support can be performed even when the inner post 12 is projected downward as much as possible to support the vehicle body. be able to.

In the above, an example in which the lower end portion 11a of the outer post 11 is drawn to reduce the fitting gap in that portion has been shown, but the present invention is not limited to this, and as shown in FIG. Any structure may be used. In this jack structure, as shown in the figure, the upper end 12a 'of the inner post 12' is formed larger (thicker) than its lower side. As a result, the fitting gap becomes extremely small only in this part. Therefore, also in this case, the rattling of the inner post 12 ′ with respect to the outer post 11 ′ is restricted and the rattling of the inner post 12 ′ is suppressed in the portion where the fitting gap is small.

Also in the case of this example, the portion where the fitting gap becomes small is only provided on the upper end portion 12a 'of the inner post 12', and even when the outer post 11 'is distorted, the inner post 12' is not supported. It can be smoothly inserted into the post 11 'and can be raised and lowered smoothly. As shown in FIG. 4 (B), the upper end 12a 'of the inner post 12' is located at a portion where the two posts 11 ', 12' overlap each other while the inner post 12 'is projected downward as much as possible. Is formed to be thick. Therefore, also in this case, the rattling of the inner stroke 12 'can be suppressed within the entire lifting stroke range of the inner post 12', and stable vehicle body support can be achieved even when the inner post 12 'is projected downward as much as possible. Can be done.

[0015]

[Effect of the device]

 As described above, according to the present invention, the fitting gap between the outer post and the inner post in the overlapping portion with the inner post protruding downward from the outer post to the maximum extent is made smaller than that in other portions. The inner post can be smoothly moved up and down in the outer post while suppressing rattling of the inner post with respect to the outer post, and the manufacturing cost thereof can be kept low.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a jack structure according to the present invention.

FIG. 2 is a perspective view of an aerial work vehicle including a jack device adopting the jack structure according to the present invention.

FIG. 3 is a perspective view showing a jack device.

FIG. 4 is a sectional view showing another example of the jack structure according to the present invention.

FIG. 5 is a sectional view showing an example of a conventional jack structure.

[Explanation of symbols]

 1 Aerial work vehicle 3 Boom 10 Jack device 11 Outer post 12 Inner post 14 Jack cylinder

Claims (1)

[Scope of utility model registration request] 1. An outer post which is attached to a side portion of a vehicle body so as to extend vertically, and an inner post which is vertically movably fitted into the outer post and is capable of projecting downward from the outer post by a predetermined length. A jack post structure, wherein a fitting gap between the outer post and the inner post in a portion overlapping with each other in a state where the inner post projects downward from the outer post to the maximum extent is made smaller than other portions. A jack post structure characterized by being constructed.