JP2008201493A - Lifting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lifting device capable of reducing frictional force generated between a roller and a mast by suppressing contact between an axial end face of the roller and the mast. <P>SOLUTION: The mast 2 erected on a base of the lifting device is made by bending a steel plate into a C-shape in plan view, and has a front surface part 21, a rear surface part 22 and a flat plate-shaped side surface part 23. The front surface part 21 to be brought into contact with the roller 3 is formed into a V-shape in plan view having contact surface parts 2a. The roller 3 has tapered surfaces 32 formed at both end parts of the axial direction. The tapered surfaces 32 correspond to the contact surface parts 2a, the contact surface parts 2a of the mast 2 are in contact with the tapered surfaces 32 of the roller 3, and the roller 3 is rotated in a state in which the lateral direction of the roller 3 is held by the front surface part 21 formed into the V-shape in plan view, and thereby unnecessary moving of the roller 3 in the lateral direction is suppressed. As a result, generation of the large frictional force due to contact of the end face 33 of the roller 3 with the side surface part 23 of the mast 2 is suppressed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lifting device for lifting various objects to be lifted.

  Elevating devices such as forklifts and electric lifters are used in factories, warehouses, and the like, and are configured to raise or lower a load placed on an elevating unit to an arbitrary height. In such an elevating device, the rollers attached to the side portions of the elevating unit come into contact with the two masts spaced apart on the left and right and rotate, so that the elevating unit is guided by the mast and smooth. (See Patent Document 1).

4 is a schematic plan view of the configuration of the mast 92 and the roller 93 included in the conventional lifting device, and FIG. 5 is a schematic front view of another configuration of the mast 92 and the roller 93. As shown in FIG. In FIG. 4, the upper side is the front side, and the lower side is the back side.
Each of the two masts 92 erected on the base of the lifting device is formed by bending an iron plate in a U shape in a plan view, and has a flat front surface portion 92a, a rear surface portion 92b, and a side surface portion 92c. Each of the front surface portion 92 a and the rear surface portion 92 b is substantially parallel to a rotation shaft portion 94 described later, and the side surface portion 92 c is substantially orthogonal to the rotation shaft portion 94.
The roller 93 is disposed inside the mast 92 and is rotatably supported by the rotary shaft portion 94. The rotary shaft portion 94 opens the U-shaped opening of the mast 92 in the left-right direction so as not to contact the mast 92. And is supported by the elevating part 91.
The front surface portion 92a and the rear surface portion 92b of the mast 92 are separated from each other longer than the outer diameter of the roller 93, and the roller 93 rotates with the circumferential surface contacting either the front surface portion 92a or the rear surface portion 92b. To do. FIG. 5 illustrates a case where the roller 93 is in contact with the rear surface portion 92b.
Further, an appropriate gap is provided between the end surface of the roller 93 and the side surface portion 92c so that the end surface (left end surface in the drawing) of the roller 93 does not contact the side surface portion 92c.

However, the lateral displacement of the roller 93 may occur due to, for example, the backlash in the lateral direction of the ascending / descending portion 91 during ascending / descending, and the end surface of the roller 93 may contact the side surface portion 92c. In addition, for example, when the distance between the upper parts of the masts 92 and 92 is different from the distance between the lower parts due to distortion, inclination, etc. of the masts 92, 92, or the weight of the elevating part 91 or placed on the elevating part 91 The end surface of the roller 93 may come into contact with the mast 92 even when the weight of the article is uneven and the elevating part 91 is inclined in the lateral direction.
Thus, when the end surface of the roller 93 and the mast 92 are in contact with each other, a large frictional force is generated.
In order to solve this problem, as shown in FIG. 4, conventionally, a sliding plate 95 having a small frictional force is provided on the side of the elevating part 91 and is slid on the outer surface of the mast 92. As a result, the lateral displacement of the roller 93 is prevented, and the end surface of the roller 93 is prevented from coming into contact with the mast 92.
Alternatively, as shown in FIG. 5, by providing an additional roller 96 whose peripheral surface contacts and rotates with the side surface portion 92 c, the lateral displacement of the roller 93 is prevented, and the end surface of the roller 93 contacts the mast 92. To prevent that.
JP 2002-15496 A

However, in the elevating device shown in FIG. 4, although the frictional force due to the contact between the end face of the roller 93 and the mast 92 is smaller, the frictional force due to the contact between the sliding plate 95 and the mast 92 is generated. The raising / lowering of the part 91 may be inhibited.
Further, in the lifting device shown in FIG. 5, since the additional roller 96 is required to be disposed, the number of parts, the assembly process, etc. are increased, and the lifting device is increased in cost.

  The present invention has been made in view of such circumstances, and its main purpose is to form a tapered surface formed at both ends of the roller in the axial direction and a V-shape or U-shape in plan view of the mast. It is providing the raising / lowering apparatus which can suppress the contact with the end surface of a roller, and a mast by setting it as the structure which contacts the inner surface which has touched.

  Another object of the present invention is to provide an elevating device that can easily form a mast having a required shape by forming a mast by bending an iron plate.

  The lifting device according to the first aspect of the present invention is standing upright apart in one direction, two masts having a C-shape in plan view and facing the opening side of the C-shape, and a lifting unit on the mast A lifting device comprising a plurality of rollers rotating in contact with a part of the inner surface of the mast and having a rotating shaft in one direction in order to be guided up and down. It is V-shaped or U-shaped, and tapered surfaces to be in contact with the part are formed at both axial ends of the roller.

  In the lifting device according to the second invention, each mast is formed by bending a plate member made of iron.

In the lifting device according to the first aspect of the invention, the shape of the portion of the mast that should contact the roller corresponds to the shape of the portion of the roller that should contact the mast. A tapered surface (hereinafter referred to as a tapered surface) to be in contact with a part of the inner surface (hereinafter referred to as an inner surface portion) is formed. The mast is formed in a C shape in plan view as a whole, and the inner surface of the mast is formed in a V shape or a U shape in plan view. Two such masts are provided upright apart in one direction, that is, in the axial direction of the roller, and the two masts face each other on the C-shaped opening side. Then, at least two rollers are provided corresponding to the number of masts.
As the taper surface of the roller comes into contact with the inner surface portion of the mast and rotates, the lifting portion is guided by the mast and moves up and down. At this time, the frictional force generated between the roller and the mast is smaller than the frictional force generated by the contact between the sliding plate provided on the axial end surface of the roller or the elevating part and the mast. That is, the elevating part can be raised and lowered very smoothly.

  Further, since the rollers are arranged so that both end portions in the axial direction are sandwiched between inner surfaces of the mast in a V shape or a U shape in plan view, the tapered surface abuts the inner surface portion, Axial movement is limited. Specifically, for example, when an external force in a direction in which the axial end surface of the roller approaches the mast is applied to the roller due to vibration of the elevating unit in the axial direction of the roller, the taper surface on the axial end surface side becomes the mast. The roller is prevented from actually approaching the mast simply by being pressed against the inner surface portion of the roller. As a result, the axial end surface of the roller is prevented from contacting the mast, and the generation of a large frictional force due to the contact between the axial end surface of the roller and the mast can be suppressed.

Furthermore, since unnecessary movement of the roller in the axial direction is suppressed, there is no need to use masts that are not distorted or to stand the masts completely in parallel, mast formation accuracy, assembly accuracy, etc. Even if the lifting device is somewhat low, contact between the mast and the axial end surface of the roller can be suppressed. Furthermore, even if the weight of the lifting part or the weight of the article placed on the lifting part is not uniform, unnecessary movement of the roller in the axial direction is suppressed, so that the lifting part is inclined in the lateral direction. The contact between the mast and the axial end surface of the roller can be suppressed.
In addition, the inner surface of the mast and the tapered surface of the roller are in contact with each other, for example, the inner surface of the mast and the right-angle axial end of the roller are not in contact with a line (in a plan view), The damage of the mast due to the contact of the roller can be suppressed. In addition, since an appropriate frictional force is generated when the inner surface portion and the tapered surface are brought into contact with each other on the surface, it is possible to suppress the inclination and idling of the roller.
In addition, since the lifting device does not need to be provided with a member such as a sliding plate or an additional roller for preventing contact between the axial end surface of the roller and the mast, the number of parts, the assembly process, etc. are not increased, and the cost can be reduced. A lifting device can be manufactured.

  In the case of the lifting device of the second invention, a mast having a required shape is formed by bending a plate member made of iron. Since bending of such a plate member is easy, the lifting device can be easily manufactured.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.

1 and 2 are a schematic side view and a schematic plan view of a lifting device 1 according to the present invention, and FIG. 3 is a schematic plan view of a mast 2 and a roller 3 provided in the lifting device 1. Here, in FIG. 1, the left side is the front side, and in FIGS. 2 and 3, the upper side is the front side.
The elevating device 1 includes an elevating unit 11 having an L-shape in side view, two masts 2 and 2 erected on a base 10 separated in the left-right direction (that is, the left-right direction in FIG. 2), and an elevating unit Are provided with four rollers 3, 3,..., And an elevator mechanism (not shown) for raising or lowering the elevator unit 11 electrically or manually.
The elevating part 11 includes a base part 11a disposed between the masts 2 and 2, and two left and right fork parts 11b and 11b that project forward from the lower part of the base part 11a and on which a load is placed. Rollers 3, 3,... Are arranged on both upper and lower sides.
The upper (and lower) two rollers 3 and 3 are rotatably supported at both ends of the rotation shaft portion 34. The rotary shaft portions 34, 34 are arranged in the left-right direction and are supported by the base portion 11 a of the elevating unit 11.

The right side (and left side) rollers 3 and 3 come into contact with a part of the inner surface of the right side (and left side) mast 2 (the front side part 21 or the rear side part 22 described later) as the elevating part 11 moves up and down. Rotate. For this reason, the elevating part 11 is guided by the masts 2 and 2 and is moved up and down in the direction of the arrow in FIG. Here, since the elevating part 11 is inclined forward and downward depending on the weight of the fork parts 11b and 11b, the weight of the article placed on the fork parts 11b and 11b, etc., the upper (and lower) two rollers 3, 3 Is in contact with the front surface portion 21 (and the rear surface portion 22) of the masts 2 and 2, and does not contact the rear surface portion 22 (and the front surface portion 21). FIG. 3 illustrates a case where the roller 3 is in contact with the front surface portion 21.
Each roller 3 is formed with a circumferential surface 31 parallel to the axial direction at the central portion in the axial direction, and tapered surfaces 32 and 32 that are inclined with respect to the axial direction are formed at both axial end portions. . The roller 3 having such a shape can be easily obtained by cutting both ends in the axial direction of a cylindrical member made of metal or synthetic resin.

Each mast 2 is C-shaped in plan view, and the left and right masts 2 and 2 are erected substantially parallel to each other with the C-shaped opening sides facing each other, and the upper parts are connected by a horizontal rail (not shown). Has been. More specifically, each mast 2 includes a front face portion 21 and a rear face portion 22 that are V-shaped in plan view and arranged in a substantially symmetrical shape about the axial direction of the roller 3, and the axial direction of the roller 3. The front surface portion 21 and the rear surface portion 22 face the inner side of the V shape so that the front surface portion 21 and the rear surface portion 22 are opposed to each other. One end of the V-shape is connected to the side surface portion 23 to form a C-shape in plan view as a whole. Here, the front surface portion 21 (and the rear surface portion 22) is formed by arranging the flat contact surface portions 2a and 2a in contact with the tapered surfaces 32 and 32 in a V shape as described later (in FIG. The description of the reference numerals of the contact surface portions 2a, 2a related to the rear surface portion 22 is omitted).
Each such mast 2 can be easily obtained by bending an appropriate position in the width direction of the iron belt-shaped flat plate member.

Each roller 3 is arranged inside the mast 2, and the rotation shaft portion 34 of the roller 3 penetrates the C-shaped opening of the mast 2 in the left-right direction so as not to contact the mast 2.
The inclination of the contact surface portions 2a, 2a of the mast 2 corresponds to the inclination of the tapered surfaces 32, 32 of the roller 3, and the tapered surface 32 is formed on the contact surface portions 2a, 2a of the front surface portion 21 (or the rear surface portion 22). , 32 are in contact with each other, the front surface portion 21 and the rear surface portion 22 are separated by an appropriate length so that an appropriate gap is provided between the rear surface portion 22 (or the front surface portion 21) and the roller 3. An appropriate gap is provided between the end surface 33 and the side surface portion 23 so that the end surface 33 of the roller 3 (more specifically, the left end surface 33 in FIG. 3) does not contact the side surface portion 23.

The elevating device 1 as described above is used in factories, warehouses, and the like, and when the elevating mechanism is operated, the load placed on the fork portions 11b and 11b of the elevating unit 11 is raised or lowered to an arbitrary height. . At this time, the taper surfaces 32 and 32 of the upper (and lower) roller 3 are rotated in contact with the contact surface portions 2 a and 2 a of the front surface portion 21 (and the rear surface portion 22) of the mast 2.
The frictional force generated between the tapered surfaces 32, 32 and the contact surface portions 2a, 2a is provided in the friction force generated by the contact between the end surface 33 of the roller 3 and the side surface portion 23 of the mast 2 or in a conventional lifting device. This is smaller than the frictional force generated by the contact between the sliding plate and the mast 2. That is, the elevating part 11 moves up and down very smoothly.

When the taper surfaces 32 and 32 come into contact with the contact surface portions 2a and 2a, the roller 3 is sandwiched between the front surface portion 21 (or the rear surface portion 22) having a V-shaped axial view in the axial direction. For this reason, unnecessary movement (that is, lateral displacement), inclination, and the like of the roller 3 in the axial direction are suppressed.
Specifically, for example, a lateral vibration is applied to the elevating part 11, and the roller 3 tries to move relative to a direction in which the end face 33 approaches the side face part 23 (that is, a white arrow direction in FIG. 3). In this case, since the tapered surface 32 on the end surface 33 side is in contact with the contact surface portion 2a, the movement of the roller 3 in the direction of the white arrow in FIG. 3 is limited.
As a result, since the end surface 33 is suppressed from contacting the side surface portion 23, generation of a large frictional force due to unnecessary contact between the roller 3 and the mast 2 is suppressed.
Further, since the rollers 3, 3,... Are restrained from being laterally displaced, the lifting and lowering portion 11 is restrained from being rattled or tilted in the lateral direction. Since the contact with the side surfaces 23 of the rollers 3, 3,... Is suppressed even with respect to the low masts 2, 2, the lifting device 1 provided with the very high masts 2, 2 (long in the vertical direction) in particular. On the other hand, the present invention is very useful.

Here, the peripheral surface 31 of the roller 3 does not contact the mast 2.
Since it is difficult to make the shape of the roller 3 almost completely correspond to the shapes of the front surface portion 21 and the rear surface portion 22 (particularly the angles of the contact surface portions 2a and 2a), if the roller 3 is not provided with the peripheral surface 31 The rotation of the roller 3 may be hindered by the difference in shape between the roller 3 and the front surface portion 21 (and the rear surface portion 22). Moreover, since the part which switches from one taper surface 32 to the other taper surface 32 makes acute angle shape, the mast 2 may be damaged. That is, the peripheral surface 31 is provided to absorb the difference in shape between the tapered surfaces 32, 32 and the contact surface portions 2a, 2a, to smoothly rotate the roller 3, and to further prevent damage to the mast 2. Yes.

Also, if a conventional cylindrical roller is provided instead of the roller 3, both end portions in the axial direction of the roller abut against the contact surface portions 2a and 2a to suppress lateral displacement. In this case, the roller is in contact surface portion 2a. , 2a, the angle of the contact surface portions 2a, 2a easily spreads by the principle of the lever with the contact position as a force point and the center position of the contact surface portions 2a, 2a as a fulcrum, and the contact surface portions 2a, 2a It may be difficult to hold the rollers between them. In order to suppress such spread of the contact surface portions 2a and 2a, it is desirable that the contact position of the roller with respect to the contact surface portions 2a and 2a be close to the center position in plan view of the contact surface portions 2a and 2a. Since the length in the axial direction is short (that is, the thickness of the roller is thin), the roller is easily damaged. In addition, since the roller and the contact surface portions 2a and 2a are in contact with a line (a point in plan view) instead of a surface, the contact surface portions 2a and 2a are easily damaged, and the roller is liable to be inclined or idle. .
That is, the roller 3 having the tapered surfaces 32 and 32 suppresses these problems.

The front surface portion 21 and the rear surface portion 22 may be formed in a U-shape, and each tapered surface 32 may have a bulge corresponding to the shape of the front surface portion 21 and the rear surface portion 22, but V-shaped than the U-shape. The mast 2 is easier to form in the letter shape.
In addition, a configuration in which a plurality of rollers arranged in parallel on the left and right contact one mast, or an inner mast and an outer mast, and a roller that contacts the inner mast that moves up and down is attached to a fixed outer mast. The structure etc. which are provided may be sufficient.

1 is a schematic side view of a lifting device according to the present invention. It is a schematic plan view of the lifting device according to the present invention. It is a schematic plan view of a mast and a roller provided in the lifting device according to the present invention. It is a schematic plan view of the structure of a mast and a roller provided in a conventional lifting device. It is a schematic front view of the other structure of the mast and roller with which the conventional raising / lowering apparatus is provided.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lifting apparatus 11 Lifting part 2 Mast 21 Front part (a part of inner surface)
22 Rear surface (part of the inner surface)
3 Roller 32 Tapered surface (tapered surface)
34 Rotating shaft (Rotating shaft)

Claims (2)

Two masts that are vertically spaced apart in one direction and that are C-shaped in plan view with the C-shaped opening side facing each other;
A lifting device comprising: a plurality of rollers having a rotating shaft in one direction, rotating and contacting a part of the inner surface of the mast so that a lifting unit is guided by the mast and moves up and down;
The part is V-shaped or U-shaped in plan view,
A lifting device characterized in that a tapered surface to be in contact with the part is formed at both axial ends of the roller.   The lifting device according to claim 1, wherein each mast is formed by bending a plate member made of iron.

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