JP4260529B2 - Hook device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hook device for lifting a load, and more particularly to a hook device suitable for performing a drop test of a product such as a motorcycle.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a hook device for lifting a load, a hook having a hook portion at a tip for hooking a load on a main body frame suspended by a lifting machine such as a crane via a wire is capable of lifting the load. A lock member that pivotally supports the position and a release position that releases the lifting of the load, and that restrains the hook to the load hanging position, and a drive source that operates the lock member to release the hook restraint. There are various known devices that eliminate the need for manual unloading work from the hook.
[0003]
For example, a concave groove is formed on the peripheral surface of the proximal end of the hook, and a lock member having a key portion that engages with the concave groove is slidably supported on the main body frame so that the lock member is an electromagnetic solenoid or the like. A device that is separated from the groove by a driving source is known (for example, see Patent Document 1). Further, a locking member is pivotally supported on the main body frame so as to be rotatable about an axis parallel to the rotation axis of the hook, and a claw portion that engages a step formed on the peripheral surface of the proximal end portion of the hook is provided on the locking member. It is also known that the lock member is formed and oscillated in a direction in which the claw part is separated from the step by a driving source such as an electromagnetic solenoid (see, for example, Patent Document 2).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 54-57755 (2nd page, FIG. 1)
[Patent Document 2]
Japanese Patent Application Laid-Open No. 7-28579 (pages 2, 3 and 1)
[0005]
[Problems to be solved by the invention]
By the way, in order to examine the strength of products such as motorcycles and small planing boats, a lock test is performed to release the product from a predetermined height by releasing the restraint of the hook by the lock member in a state where the product is lifted using the hook device. There is.
[0006]
Here, in the above-mentioned conventional example, when the hook of the lock member is released, the engagement portion (key portion or claw portion) of the lock member with respect to the hook is against the engagement surface such as the groove wall surface or the step surface of the hook. Slide. When the drop test is performed, the engagement portion of the lock member is engaged with the hook while the engagement surface of the hook and the engagement portion of the lock member are in strong pressure contact with a rotational moment corresponding to the weight of the product acting on the hook. It will slide against the surface.
[0007]
For this reason, the force required to disengage the engaging portion of the lock member from the engaging surface of the hook becomes large, and the drive source must be enlarged. Wear on the engaging surface is likely to occur and durability is reduced. Further, the smoothness of the operation of the lock member may be impaired due to galling between the engagement portion of the lock member and the engagement surface of the hook, and the timing for releasing the restraint of the hook may be shifted or may not be released. In particular, in the product drop test, accurate test data cannot be obtained unless the restraint of the hook is released smoothly.
[0008]
In view of the above, it is an object of the present invention to provide a small-sized and highly durable hook device capable of ensuring smoothness of a hook restraint releasing operation.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a hook device for lifting a load, and a hook having a hook portion at a tip end for hooking a load on a main body frame, and a load lifting position capable of lifting the load. And a lock member that pivotally supports the release position for releasing the load and that restrains the hook at the load suspension position, and a drive source that operates the lock member to release the hook restraint. In this structure, a roller serving as an engaging portion for the hook is pivotally attached to the lock member , the roller is brought into contact with a flat engagement surface formed on the hook, and the hook is constrained to the load hanging position. Is supported on the body frame so as to be rotatable about an axis parallel to the rotation axis of the hook, and the lock member is restrained by the pressing force acting on the roller from the engagement surface in a state where the hook is in the load hanging position. The lock member is configured to receive a rotational moment in the unlocking direction that releases the lock, and is engaged with a portion of the lock member that is longer than the roller by the distance from the rotation axis of the lock member to the main body frame. Is provided with an engagement member that prevents the hook from rotating in the unlocking direction from the lock position that restricts the hook to the load suspension position, and the engagement member is operated by the drive source so that the engagement with the lock member is released. It is characterized by.
[0010]
According to said structure, a roller rolls with respect to an engagement surface when canceling | releasing the restraint of the hook by a locking member. Accordingly, the hook is smoothly released without causing galling between the lock member and the hook. Further, wear due to sliding between the lock member and the hook during the restraint releasing operation does not occur, and durability is improved.
[0011]
By the way, the lock member is composed of a direct-acting member that is slidably supported by the main body frame, and the engagement surface is parallel to the sliding direction of the lock member in a state where the hook is in the load hanging position. At the same time, the roller is pivotally attached to the lock member so as to come into contact with the engagement surface from the normal direction, and the lock member is slid in the direction in which the roller is removed from the engagement surface by the drive mechanism, thereby releasing the restraint of the hook. It is conceivable to configure so as to. However, this causes sliding friction between the main body frame and the lock member, so that the drive source cannot be miniaturized to the left, and wear and galling may occur. In order to solve these problems, it is necessary to support the lock member on the main body frame via the linear guide, which increases the cost.
[0012]
On the other hand, if the lock member is composed of a lever member that is pivotally supported by the main body frame about an axis parallel to the rotation axis of the hook, wear due to sliding friction between the main body frame and the lock member. It becomes difficult to generate galling. Here, in a state where the hook is in the load hanging position, the action line of the pressing force acting on the roller from the engagement surface is in a neutral state where it coincides with a line connecting the roller axis and the rotation axis of the lock member. If this is the case, the lock member does not receive a rotational moment due to the pressing force. Then, by applying a small driving force in the unlocking direction to release the restraint of the hook to the locking member, the hook will then rotate the locking member in the unlocking direction with its own rotating moment due to the weight of the load. Rotates from the suspended position to the released position. However, in order to achieve the neutral state when the hook is in the load hanging position, the relative position accuracy of the hook rotation axis, the lock member rotation axis, the engagement surface and the roller is managed with extremely high accuracy. Need to be and is not realistic. Therefore, in a state where the hook is in the load hanging position, the locking member must be configured to receive a rotational moment in the unlocking direction or in the direction opposite to the unlocking direction by the pressing force acting on the roller from the engagement surface. Absent.
[0013]
Here, if the lock member is configured to receive a rotational moment in a direction opposite to the unlocking direction by the pressing force acting on the roller from the engagement surface in a state where the hook is in the load hanging position, the lock member is The hook is self-locked at a lock position that restrains the hook at the load hanging position. However, in this case, when the lock member is rotated from the lock position in the unlock direction, the hook is rotated from the load suspension position in the direction of once lifting the load. Therefore, a large force is required to rotate the lock member from the lock position in the unlock direction, and it is difficult to reduce the size of the drive source.
[0014]
On the other hand, if the lock member is configured to receive a rotational moment in the unlocking direction by the pressing force acting on the roller from the engagement surface in a state where the hook is in the load hanging position, the lock member is moved from the lock position. No external force is required to rotate the unlock position. On the other hand, in this case, the lock member is not self-locked to the lock position. Therefore, the main body frame is provided with an engagement member that engages and prevents the lock member from rotating in the unlocking direction from the lock position so that the engagement of the engagement member with the lock member is released. It is necessary to operate with a drive source. If the engaging member is engaged with the portion of the locking member whose distance from the rotation axis of the locking member is longer than that of the roller, the force acting between the engaging member and the locking member is increased. This principle is alleviated. Therefore, the force required to operate the engaging member is also reduced, and the drive source can be reduced in size.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a hook device used when a drop test of a product such as a motorcycle or a small planing boat is performed will be described. Referring to FIGS. 1 to 3, reference numeral 1 denotes a main body frame of the hook device, and a connecting ring 2 for connecting a wire extending from a lifting machine such as a crane is provided at the upper end of the main body frame 1.
[0016]
The main body frame 1 is configured by fastening a pair of left and right side plates 3 and 3 with bolts 5 with a spacer 4 interposed therebetween. The connecting ring 2 is screwed onto the upper end of a support bar 2a bolted between the side plates 3 and 3. Leg pieces 3a, 3a are suspended at the lower ends of the side plates 3, 3 so as to be biased to the rear side (right side in FIGS. 1 and 3), and are loaded between the leg pieces 3a, 3a. A hook 6 having a hook portion 6b at the tip for hooking the hanging strap of the product is pivotally supported by a support shaft 6a. Then, the hook 6 can be lifted by a load (position shown by a solid line in FIG. 3) where the product can be lifted, and a release position (the phantom line shown in FIG. 3) where the hook 6 is directed downward to release the product. Position).
[0017]
The lower end of the leg piece portion 3a is formed in a semicircular shape concentric with the support shaft 6a, and a stopper pin 6c is provided on the hook 6 so as to move along the lower end edge of the leg piece portion 3a by its rotation. Yes. When the hook 6 is rotated to the load hanging position, the stopper pin 6c comes into contact with the front edge of the boundary with the semicircular lower end of the leg piece 3a, and the hook 6 rotates beyond the load hanging position. I try not to.
[0018]
Further, a claw piece 7 reaching the vicinity of the tip of the hooking portion 6b of the hook 6 is suspended from the lower front side of the main body frame 1, and the claw piece 7 indicates that the hanging string jumps out of the hooking portion 6b due to vibration during conveyance. To prevent it. The claw piece 7 is swingable with the upper shaft 7a as a fulcrum, and is biased and held by a spring 7c at a closed position (position shown in the figure) regulated by the stopper pin 7b. When the hanging string is hooked on the portion 6b, the claw piece 7 is opened rearward against the spring 7c.
[0019]
The main body frame 1 is further provided with a lock member 8 for restraining the hook 6 at the load hanging position, and a drive source 9 for operating the lock member 8 so as to release the restraint of the hook 6. The lock member 8 is constituted by a lever-like member which is vertically supported between the side plates 3 and 3 of the main body frame 1 and is pivotally supported by a support shaft 8a which is parallel to the support shaft 6a of the hook 6. Yes. The support shaft 8 a is located near the lower end of the lock member 8. And the roller 10 used as the engaging part with respect to the hook 6 is rotatably pivotally supported by the support shaft 10a at the lower end portion of the lock member 8 located obliquely rearward and downward with respect to the support shaft 8a.
[0020]
The hook 6 is formed with a planar engagement surface 6d that is in contact with the roller 10 at the upper end of the portion extending upward from the support shaft 6a. Then, the hook 6 is constrained to the load hanging position by rotating and holding the lock member 8 at the lock position (shown position) where the roller 10 abuts against the engaging surface 6d of the hook 6 existing at the load hanging position. I have to.
[0021]
Referring to FIG. 4, O1 is the position of the rotation axis of hook 6 (center of support shaft 6a), O2 is the position of the rotation axis of lock member 8 (center of support shaft 8a), and O3 is the position of lock member 6. This is the position of the rotation axis of the roller 10 (center of the support shaft 10a) when in the locked position. The engagement surface 6d has a point P where the roller 10 abuts in a state where the hook 6 is in the load hanging position on the rear side of the intersection N with the engagement surface 6 of a line perpendicular to the engagement surface 6 passing through O1. The pressing force F acts on the roller 10 from the engaging surface 6d by the rotational moment M of the hook 6 in the release position side (counterclockwise in FIG. 4) due to the weight of the product.
[0022]
Further, O2 and O3 and the engaging surface 6d are so arranged that the line connecting O2 and O3 with respect to the line of action of the pressing force F is inclined in the unlocking direction (counterclockwise in FIG. 4) for releasing the restraint of the hook 6. The relative positional relationship of is set. Therefore, the lock member 8 receives the rotational moment m in the unlocking direction by the pressing force F acting on the roller 10 from the engaging surface 6d in a state where the hook 6 is in the load hanging position.
[0023]
The locking member 8 is prevented from rotating beyond the locking position in the direction opposite to the unlocking direction (hereinafter referred to as the locking direction) by the stopper 8b fixed to the main body frame 1 that is in contact with the upper rear edge thereof. It has come to be. A spring 8c that biases the lock member 8 in the lock direction is provided so that the lock member 8 is biased and held at the lock position in the free state.
[0024]
In addition, an arc-shaped recess 8d is formed at the upper end of the front edge of the lock member 8, and the shaft has an arc-shaped outer peripheral surface that engages the recess 8d when the lock member 8 is in the locked position. The engagement member 11 is provided so that the lock member 8 can be prevented from rotating in the unlocking direction from the lock position. The engaging member 11 is rotatably supported between the side plates 3 and 3 of the main body frame 1. When the engagement member 11 is formed with a substantially semicircular cutout portion 11a and the engagement member 11 is rotated counterclockwise in FIG. 3, the cutout portion 11a reaches the upper end of the recess portion 8d. The lock member 8 is disengaged from the engagement member 11 and rotates in the unlocking direction from the lock position.
[0025]
Here, the engagement member 11 is configured to be rotationally driven by the drive source 9 via the lever 12. In detail, a shaft portion 11b that penetrates one side plate 3 of the main body frame 1 and extends outward is formed integrally with the engaging member 11, and a lever 12 that is long in the front-rear direction is formed on the shaft portion 11b. A cylindrical portion 12a fixed to the rear end portion is externally fitted and is prevented from rotating by a key 12b. The drive source 9 is composed of an electromagnetic solenoid attached to the outer surface of one side plate 3 of the main body frame 1 via a bracket 13. The electromagnetic solenoid includes a movable plunger 9a protruding upward, and a front end portion of the lever 12 is inserted into a fork portion 9b at an upper end thereof. And the pin 9c inserted in the cylinder part 12c fixed to the front-end part of the lever 12 is being fixed to the fork part 9b. Thus, the engagement member 11 is rotated counterclockwise through the lever 12 by the downward movement of the movable plunger 9a by energization of the electromagnetic solenoid, and the engagement of the engagement member 11 with the lock member 8 is released as described above. .
[0026]
In addition, the inner periphery of the cylinder part 12c is formed in the cross-sectional oval shape long in the front-back direction. The lever 12 is urged clockwise by a tension spring 12e stretched between a tongue piece 12d protruding rearward from the rear end portion and the bracket 13. Then, the clockwise rotation of the lever 12 is regulated at a fixed position by a stopper 12f attached to the side plate 3 so that the engagement member 11 is normally biased and held in a state of being engaged with the lock member 8. ing.
[0027]
Further, the hook 6 is formed with an engagement hole 6e that is positioned slightly above the support shaft 6a, and a safety pin 14 that is loosely inserted into the engagement hole 6e through the other side plate 3 of the main body frame 1 is provided. Thus, even if the restraint of the hook 6 by the lock member 8 is released during the conveyance of the product, the safety pin 14 can prevent the hook 6 from rotating to the release position. The safety pin 14 is inserted into and removed from the engagement hole 6e via the link mechanism 16 by an electromagnetic solenoid 15 attached to the outer surface of the other side plate 3.
[0028]
In the product drop test, the product frame is lifted by lifting the main body frame 1 with a lifting machine while the product hanging string is hooked on the hook 6b of the hook 6, and the product is transported to the test place in this state. Then, when the lifting height of the product is adjusted to a predetermined test height, the safety pin 14 is separated from the engagement hole 6e by the electromagnetic solenoid 15 and the engagement member 11 is rebounded by the drive source 9 via the lever 12. The engagement member 11 is disengaged from the lock member 8 by rotating clockwise.
[0029]
Here, a rotational moment in the unlocking direction is applied to the lock member 8 by the pressing force F acting on the roller 10 from the engagement surface 6 d of the hook 6, and the lock member 8 is engaged with the recess 8 d on the upper end of the lock member 8. While the member 11 is engaged, the recessed portion 8d is pressed against the engaging member 11 by the force of this rotational moment. When the engagement of the engagement member 11 with respect to the lock member 8 is released, the engagement member 11 rotates and slides against the recessed portion 8d in a pressure contact state. However, the distance between the recessed portion 8d and the support shaft 8a is longer than the distance between the roller 10 and the support shaft 8a, and the pressure contact acting between the recessed portion 8d and the engaging member 11 by the lever principle. The power does not increase as much as the left. Therefore, wear and galling between the recessed portion 8d and the engagement member 11 are effectively suppressed, and furthermore, a driving force required to rotate the engagement member 11 can be reduced.
[0030]
When the engagement of the engagement member 11 with the lock member 8 is released, the restraint at the load hanging position of the hook 6 by the lock member 8 is also released. The hook 6 rotates from the load suspension position to the release position while rotating the lock member 8 in the unlocking direction by its own rotational moment due to the weight of the product. As a result, the hanging string comes off from the hook 6b of the hook 6, and the product falls. Here, when the lock member 8 rotates in the unlock direction from the lock position, the roller 10 rolls on the engagement surface 6 d of the hook 6. Therefore, wear due to sliding friction between the hook 6 and the lock member 8 does not occur, and no galling occurs between the lock member 8 and the hook 6, and the hook 6 is moved from the load hanging position to the release position. It is rotated smoothly.
[0031]
As described above, according to the present embodiment, wear due to sliding friction between the hook 6 and the lock member 8 is prevented, and wear between the lock member 8 and the engagement member 11 is also effective. Since it is suppressed, durability is improved. Further, since the galling between the hook 6 and the lock member 8 and between the lock member 8 and the engagement member 11 is prevented, the restraint at the load hanging position of the hook 8 can be released smoothly. Further, since the driving force of the engaging member 11 can be small, a small drive source 9 can be used, and the hook device as a whole can be downsized.
[0032]
As mentioned above, although embodiment which applied this invention to the hook apparatus used by the drop test of a product was described, this invention is applicable similarly to the hook apparatus for normal cargo handling.
[Brief description of the drawings]
FIG. 1 is a front view of an example of a hook device of the present invention.
FIG. 2 is a side view of the hook device as viewed from the right side of FIG.
3 is a cross-sectional view taken along line III-III in FIG. 1. FIG. 4 is a diagram showing the positional relationship between the pressing force acting on the roller from the engagement surface of the hook and the rotation axis of the lock member.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Main body frame 6 ... Hook 6a ... Hook support shaft 6b ... Hook 6d ... Engagement surface 8 ... Lock member 8a ... Lock member support shaft 9 ... Drive source 10 ... Roller 11 ... Engagement member

Claims (1)

A hook device for lifting a load, wherein a hook having a hook portion at a tip for hooking a load is rotated on a main body frame between a load lifting position where the load can be lifted and a release position where the lifting of the load is released. In what is provided with a lock member that pivotally supports the hook and restrains the hook at the load hanging position, and a drive source that operates the lock member to release the restraint of the hook.
A roller serving as an engaging portion for the hook is pivotally attached to the lock member, and the roller is brought into contact with a flat engaging surface formed on the hook so that the hook is restrained at the load hanging position .
The lock member is pivotally supported on the main body frame so as to be rotatable about an axis parallel to the rotation axis of the hook, and the lock member is hooked by the pressing force acting on the roller from the engagement surface in the state where the hook is in the load hanging position. It is configured to receive a rotational moment in the unlocking direction to release the restraint, and the main body frame is engaged with a portion of the lock member that is longer than the roller from the rotation axis of the lock member, An engagement member that prevents the lock member from rotating in the unlocking direction from the lock position that restrains the hook at the load hanging position is provided, and the engagement member operates with the drive source so that the engagement with the lock member is released. hook and wherein the letting.

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