JP2003238087A - Fork lift truck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a pallet from slipping or swinging on a fork. <P>SOLUTION: This fork lift truck has a load supporting means provided with the fork 6 inserted in the pallet P for placing a load W, and a lift bracket 4 for supporting the fork 6; and a lifting means for lifting the load supporting means. The load supporting means is provided with pallet locking devices 11, 31, 51 for locking the pallet P with the fork 6 inserted therein, by pressing the inner lower face of the pallet P, i.e., the upper face of a lower deck board, interlocked with the relative ascent of the fork 6 to the pallet P. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forklift equipped with a pallet lock device for locking a pallet lifted by a fork so that the pallet does not accidentally shift on the pallet during transportation.

[0002]

2. Description of the Related Art FIG. 5 shows an example of a reach type forklift. This is composed of a vehicle body 1 and a pair of left and right straddle legs 2 protruding in front of the vehicle body 1. The vehicle body 1 and the straddle leg 2 are provided with rear wheels 1a and front wheels 1 respectively.
b is provided. A pair of left and right masts 3 are provided along the straddle leg 2 so as to be movable in the front-rear direction of the vehicle body. A lift bracket 4 is arranged on the mast 3 so as to be movable up and down, and a lift bracket 4 is moved up and down. A lift cylinder 5 as an elevating means is arranged.
Further, a pair of left and right forks 6 in a side view are supported by the lift bracket 4, and the fork 6 is moved up and down along with the lift bracket 4 along the mast 3 by the lift cylinder 5. P is a pallet having a hole Ph therein, and by inserting the fork 6 into the hole Ph, the fork 6 is lifted and conveyed by the fork 6 together with the load W placed on the upper surface thereof. Reference numeral 7 denotes a driver's seat arranged at the rear portion of the vehicle body, and various levers 8 provided on the driver's seat are used for traveling the vehicle body 1 and driving the lift cylinder 5.
This is performed by the operator operating the above items. In addition,
The fork 6 is attached to the lift bracket 4 by a shaft 9.
On the other hand, the load W can be tilted up and down within a predetermined angle, and when the load W is conveyed together with the pallet P, the load W is not easily collapsed by tilting the fork 6 slightly upward by a device (not shown). Done in.

[0003]

In the conventional forklift described above, when carrying work is performed in a place where dew condensation is likely to occur on the pallet P, such as in a freezer, or when a synthetic resin pallet having a small friction coefficient is used. And so on
The pallet P may slip on the fork 6 and be displaced, causing a load collapse.

As described above, the possibility of load collapse is reduced by tilting the fork 6 slightly upward, but it is still impossible to prevent the pallet P from slipping on the fork 6 and the load collapse occurs when the vehicle body turns. Inevitably occurs. Further, when carrying the load W only for a short distance, it is troublesome to tilt the fork, so that the carrying work is often carried out while the fork 6 is in a horizontal posture. P slippage is likely to occur.

In view of the above-mentioned problems, the present invention first of all fixes the pallet by locking the pallet so that the pallet does not slip, misalign, or swing on the fork. It is an object of the present invention to provide a forklift capable of preventing such problems. A second object of the present invention is to provide a forklift that can reliably prevent the pallet from slipping even when the fork is not tilted up and down.

[0006]

In order to achieve the above object, as a first aspect of the present invention, a load support including a fork inserted into a pallet for placing a load and a lift bracket for supporting the fork. A forklift having a means and an elevating means for elevating and lowering the load supporting means, wherein the pallet inserted into the fork is linked to the load supporting means in association with a relative ascent of the fork with respect to the pallet. A forklift is provided with a pallet lock device that locks the inner lower surface by pressing.

According to the first aspect of the invention, the pallet lock device for locking the pallet inserted in the fork is provided, and the pallet lock device is operated in association with the relative raising of the fork with respect to the pallet. Since this is done, the pallet can be locked at the moment of lifting it with a fork. Therefore, even if the fork is not tilted, the pallet will never slip or swing on the fork. Moreover, since the pallet lock device is adapted to press the inner lower surface of the pallet, that is, the upper surface of the lower deck board, it is possible to place a load on all of the upper surface of the pallet, that is, the upper surface of the upper deck board, and Loads can be loaded and transported. It is preferable that the pallet lock device mechanically operates in conjunction with the relative lifting of the fork because of its simple structure, low cost, and few failures. In the present invention, the load supporting means is a general term indicating the fork and the lift bracket, and therefore the pallet lock device may be provided on any of the fork and the lift bracket. Further, in the present invention, the lifting means means, for example, a mast or a lift cylinder.

A second invention is the forklift according to the first invention, wherein the pallet locking device unlocks the pallet in conjunction with the relative lowering of the fork with respect to the pallet. provide.

According to the second invention, the pallet is unlocked at the moment when the pallet is placed on the ground or on the shelf, so that the unloading work becomes extremely easy. Moreover, since no special manual device or manual operation for unlocking is required, efficient unloading work can be realized.

As a third aspect of the invention, in the first or second aspect of the invention, the pallet lock device is a movable member that comes into contact with the pallet and is displaced when the fork is raised, and is interlocked with the displacement of the movable member. And a lock bar that presses the pallet with a lock bar.

According to the third aspect of the invention, the pallet lock device includes a movable member that comes into contact with the pallet when the fork is raised and is displaced, and a lock bar that presses the pallet in conjunction with the displacement of the movable member. Since the movable member comes into contact with the pallet, it is possible to reliably detect the rise of the fork and ensure the operation timing of the lock bar. That is,
This is because if the pallet is locked at a timing when the relative rise of the fork with respect to the pallet is insufficient, the pallet may swing at that moment due to the locking operation and the load may collapse. Since the size and shape of the pallet are not constant and the height of the fork inserted into the pallet is not constant, it is difficult to set the timing for locking the pallet without rocking it. This locking operation can be executed at a suitable timing. The movable member and the lock bar may be integrated with each other or may be separate members.
Invention includes both of them.

As a fourth invention, there is provided a forklift according to the third invention, characterized in that the lock bar is provided with an elastic member for elastically pressing the pallet.

According to the fourth invention, it is possible to widely deal with pallets having different sizes and various pallets having different hole positions as described above. Even if the height position of the lower deck board with respect to the upper deck board is different,
Since the elastic member absorbs this variation in height, the inner lower surface of the pallet, that is, the upper surface of the lower deck board can be reliably pressed. The elastic member is usually a spring, but any member having an elastic force may be used, and a leaf spring or the like may be used. The elastic member does not necessarily have to be directly provided on the lock bar, but may be indirectly provided via some member, or may be provided between the movable member and the lock bar. Such cases are also included.

As a fifth aspect of the invention, in the third or fourth aspect of the invention, the movable member and the lock bar are both biased upward by a spring, and the movable member is moved from the upper surface of the fork by the spring. The forklift is urged by the protrusion and pressed by the pallet to be displaced downward, and the lock bar is moved downward against the spring with displacement of the movable member. I will provide a.

According to the fifth aspect of the invention, since the movable member is biased upward by the spring, when the fork rises and the upper surface of the fork reaches substantially the same height as the lower surface of the upper deck board of the pallet. The displacement amount of the movable member reaches a predetermined value, and the predetermined displacement amount is transmitted to the lock bar, so that the operation of the lock bar becomes reliable. Further, since the lock bar is also biased upward by the spring, it is possible to receive the displacement of the movable member and perform a reliable operation according to the displacement amount. Further, this spring can also be used as the elastic member in the above-mentioned fourth invention.

As a sixth invention, in the third to fifth inventions, the movable member and the lock bar are integrally formed with each other, and the movable member is pressed downward by the pallet and is displaced downward. Only by moving the lock bar downward, the movable member presses the inner upper surface of the pallet and the lock bar presses the inner lower surface of the pallet.

According to the sixth aspect of the present invention, the movable member and the lock bar are integrally formed with each other and move integrally, so that the pallet can be reliably locked with a very simple structure. . Further, the inner top surface of the pallet, that is, the lower surface of the upper deck board is pressed by the fork and the movable member, and the inner lower surface of the pallet, that is, the upper surface of the lower deck board is pressed by the lock bar. it can.

As a seventh invention, in the above third to fifth inventions, the lock bar is supported so as to be vertically rotatable about an axis, and a spring is arranged between the lock bar and the load supporting means. The spring is arranged such that the spring or an extension thereof crosses the shaft as the lock bar turns, and the movable member is arranged when the movable member is displaced by being pressed by the pallet. A forklift is provided that is arranged to operate to pivot the lock bar downwards.

According to the seventh aspect of the present invention, the lock bar is biased upward by the spring before the fork is raised, and when the movable member is pressed and displaced by the pallet, the spring is biased. The direction is reversed and the lock bar is urged downward by the spring to pivot and press the pallet. Therefore, the lock bar can be swiftly operated according to a slight displacement of the movable member, and a pallet lock device having a simple structure can be realized.

As an eighth invention, in the third or fourth invention, the lock bar is biased downward by a spring, and the movable member restricts the downward movement of the lock bar. A locking portion is formed, and when the movable member is pressed and displaced by the pallet, the lock bar relaxes or releases the restriction by the locking portion and moves downward by the urging force of the spring. To provide a forklift.

According to the eighth aspect of the invention, when the movable member is pressed and displaced by the pallet, the lock bar is relaxed or released from the restriction of movement by the engaging portion, and is urged downward by the spring to pivot. Press the pallet. Therefore, according to the eighth aspect of the invention, the lock bar can be actuated swiftly in response to a slight displacement of the movable member, and a pallet lock device having a simple structure can be realized.

The above-mentioned first to eighth inventions can take various forms depending on the mode for carrying out the invention.
The present invention includes all of these forms without departing from the gist thereof. However, the pallet locking device in the forklift according to the present invention locks the pallet by pressing the inner lower surface of the pallet, that is, the upper surface of the lower deck board, for example, by engaging the upper deck board of the pallet or It does not press this. According to the present invention, the pallet is pressed from above and below in both vertical directions by performing up and down movements of the fork and downward movement by the pallet locking device, which are mutually opposite operations. It is performed almost simultaneously with the ascending movement of the fork. Accordingly, the present invention does not refer to such things as contacting an upper deck board to engage or press the upper deck board, or contact a lower deck board to engage or press the lower deck board. The technical idea is fundamentally different, and it is also clearly different from the technique of manually locking the pallet after lifting it with a fork.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The overall outline of the reach type forklift according to the present invention is basically the same as that shown in FIG. Therefore, in the following description, the same reference numerals will be used for the members described in FIG. 5, and detailed description thereof will be omitted.

FIG. 1 shows the first embodiment of the present invention.
This will be described with reference to FIGS. 2a and 2b. FIG. 1 shows a schematic view of a forklift truck seen from above (head guards and the like are omitted). FIG. 2a shows a pallet P grounded on the ground or the like.
2b shows a state in which the fork 6 is inserted into the hole Ph, and FIG. 2b shows a state in which the fork 6 is lifted from the state of FIG. 2a.
The thing which looked at a pair of forks 6 from the inside is shown. A pair of left and right pallet lock devices 11, which are enlarged and shown in the circle, are arranged close to the inside of each fork 6.

The pallet lock device 11 includes a bracket 12 fixed to the inner surface of the bent portion of the fork 6, a lock member 14 rotatably supported by the bracket 12 by a shaft 13, the bracket 12 and the lock member 14. And a spring 15 stretched between the two. The lower end of the bracket 12 projects toward the rear of the vehicle body with respect to the fork 6, and the shaft 13 is arranged at the projecting portion. The spring 15 is vertically provided on a vertical portion of the fork 6, and its upper end is fixed to a pin 16a fixed to an upper portion of the bracket 12, and its lower end is fixed to a position closer to the front of the vehicle body than the shaft 13 of the lock member 14. Are engaged with the respective pins 16b. The lock member 14 is integrally formed of a portion of a movable member 17 that projects in a substantially circular shape so as to largely bulge upward and a portion of a lock bar 18 that is integral with the movable member 17. The lock bar 18 includes a leaf spring 19 as an elastic member extending from the lower portion of the movable member 17 to the front thereof, and a friction member 20 fixed to the tip of the leaf spring 19. Friction member 20
Is formed of a member having a large friction coefficient such as rubber, or has a knurled surface or the like for increasing frictional force on its lower surface.

In the state of FIG. 2a, the locking member 14 is
The spring 15 pivots clockwise about the shaft 13 in the clockwise direction in the drawing and pulls it upward, and its upper edge abuts on a stopper 21 projecting from the bracket 12 to stop the stopper. In the state of FIG. 2a, the lock member 14 is arranged such that the lower edge thereof is parallel to the fork 6 and the portion excluding the movable member 17 is included in the vertical range of the fork 6 in a side view. Further, in this state, the movable member 17 projects upward from the upper surface of the fork 6, and the entire lock member 14 including the movable member 17 is vertically spaced above and below the gap 22a,
The vertical dimension is set so that it can be positioned inside the hole Ph of the pallet P, leaving 22b. Therefore, when the fork 6 is inserted into the hole Ph of the pallet P, the pallet lock device 11 does not interfere with the pallet P and the hole P is not interfered with.
It is smoothly inserted into h.

Explaining an example of the unloading work, when the fork 6 is inserted into the pallet P and the fork 6 is lifted from the state of FIG.
The relative height relationship with and changes, the upper skimmer 22a is gradually smaller, and the lower skimmer 22b is gradually larger. When the clearance 22a becomes zero and the movable member 17 comes into contact with the inner upper surface of the pallet P, that is, the lower surface of the upper deck board P1 forming the pallet, the movable member 17 is pressed downward, whereby the lock member 14 is pressed. Rotates downward about the shaft 13 against the force of the spring 15. Before the fork 6 contacts the lower surface of the upper deck board P1, that is, before the movable member 17 is displaced to the upper surface of the fork 6, the friction member 20 is moved to the pallet P.
The length of the leaf spring 19 is set so as to come into contact with the inner bottom surface of the lower deck board P2, that is, the upper surface of the lower deck board P2, and the friction member 20 comes into contact with the lower deck board P2 and applies a pressing force thereto. Immediately after that, the fork 6 is placed on the upper deck board P.
Touch 1 and press it. That is, in the state of FIG. 2b, the movable member 17 contacts the lower surface of the upper deck board P1 together with the fork 6 and presses the movable member 17 upward, and the friction member 20 of the lock bar 18 contacts the upper surface of the lower deck board P2. It touches and presses it downwards. Further, at this time, the leaf spring 19 is bent slightly and continues to apply a pressing force to the friction member 20. Further, when the vertical dimension of the hole Ph of the pallet P has a variation, the leaf spring 19 has an action of absorbing the variation due to the bending.

As a result, the pallet P is locked by the upward and downward pressing force from the inside thereof, and the pallet P is not easily detached from the fork 6. The state shown in FIG. 2b is maintained even if the fork continues to rise, and therefore, the pallet P is prevented from slipping, shifting, swinging, etc., and the load W on the pallet P is prevented from collapsing. It is kept stable without occurring.

When the transfer of the load W by the forklift is completed and the load W is unloaded together with the pallet P on another ground or shelf, the pallet lock device 11 moves from FIG. 2b to FIG. 2a. The opposite operation is performed.
That is, when the pallet P comes into contact with the above-mentioned shelf or the like and stops the lowering operation, the continuous lowering operation of the fork 6 causes
The upper surface of the fork 6 separates from the upper deck board P1. Along with this, the posture of the lock member 14 is also changed by the force of the spring 15 so that the inclination angle becomes smaller, and the friction member 20 separates from the lower deck board P2.
The original state shown in FIG. 2a is restored.

As a result, the pallet P is released from the locked state, and by moving the fork 6 rearward from this state, the fork 6 is separated from the pallet P and the unloading is completed. Therefore, according to the above-described first embodiment, the pallet P is firmly locked on the fork 6 from the loading operation to the unloading operation, and does not slip or swing. Further, the pallet locking operation in the unloading operation and the unloading operation does not require any manual work by an operator, and does not require a drive source such as a motor or a cylinder device or an electric means, and has a simple mechanism. Definitely done.

In the first embodiment, the lock member 14 is formed integrally with the movable member 17 and the lock bar 18, but the movable member 17 and the lock bar 18 are separated from each other. It is also possible to form the body, for example, to arrange a spring between the two.
Further, although the pallet lock device 11 is provided on the fork 6, it may be provided on the lift bracket 4 as in the second embodiment described later.

Next, a second embodiment will be described with reference to FIGS. 3a and 3b. It should be noted that FIG. 1 can be applied to the second embodiment almost in common. Similar to the case of the first embodiment described above, FIG. 3a shows a state in which the fork 6 is inserted into the hole P1 of the pallet P grounded on the ground or the like, and FIG. 3b shows that the fork 6 is lifted from the state of FIG. 3a. Shows the closed state. A pair of left and right pallet lock devices 31 enlargedly shown in the circle are arranged close to the inside of each fork 6.

The pallet lock device 31 includes a bracket 32 fixed to the lower portion of the lift bracket 4, a lock member 34 rotatably supported on the bracket 32 by a shaft 33, and the bracket 32 and the lock member 34. And a spring 35 stretched between the two. The bracket 32 has an L-shape that is bent toward the front of the vehicle body so that the lower end of the bracket 32 is at the same height as the horizontal portion of the fork 6, and the shaft 33 is disposed in the horizontal portion. The spring 35 is provided in a substantially horizontal direction along the horizontal portion of the fork 6, the rear end of which is a pin 36a fixed to the bent portion of the bracket 32, and the tip of which is closer to the front of the vehicle than the shaft 33 of the lock member 34. The pins 36b fixed in position are engaged with each other. The lock member 34 has a portion of a movable member 37 protruding in a substantially circular shape so as to largely bulge upward, and the movable member 37.
And a portion of the lock bar 38 which is integrated with the above.

In the state of FIG. 3a, the spring 35 is
Is set so that its center line 35a (that is, a straight line connecting both pins 36a and 36b) is located above the center of the shaft 33. Therefore, the lock member 34 is urged in the clockwise direction in the drawing by the spring 35 in the clockwise direction around the shaft 33 to be pulled upward, and its upper edge is brought into contact with the stopper 41 projecting from the bracket 32 to stop the lock member 34. Has been done. In the state of FIG. 3a, the lock member 34 is arranged such that the lower edge thereof is parallel to the fork 6 and the portion excluding the movable member 37 is included in the vertical range of the fork 6 in a side view. Further, in this state, the movable member 37 projects upward from the upper surface of the fork 6, and the entire lock member 34 including the movable member 37 is positioned inside the hole Ph of the pallet P leaving the gaps 42a and 42b above and below the lock member 34. The vertical dimension is set so that it can be done. Therefore, when the fork 6 is inserted into the hole Ph of the pallet P, the pallet lock device 31 is smoothly inserted into the hole Ph without interfering with the pallet P.

Explaining an example of the unloading work, when the fork 6 is inserted into the pallet P and the fork 6 is lifted from the state of FIG.
The relative height relationship with and changes such that the upper clearance 42a gradually becomes smaller and the lower clearance 42b gradually becomes larger. When the clearance 42a becomes zero and the movable member 37 comes into contact with the inner upper surface of the pallet P, that is, the lower surface of the upper deck board P1 forming the pallet, the movable member 37 is pressed downward to cause the lock member 34 to move. Rotates downward about the shaft 33 against the force of the spring 35. As the lock member 34 turns, the center line 35a of the spring 35 also turns downward about the pin 36a at the rear position of the vehicle body. When the lock member 34 pivots by a predetermined angle, the center line 35a crosses the pivot shaft 33 of the lock member 34 from the upper side to the lower side, and is located below the center line 35a.
Then, the spring 35 acts so as to urge the lock member 34 downward about the shaft 33, that is, reverses the direction of the urging force from above to below, whereby the lock member 34 moves downward. Turn and its rock bar 3
The tip portion of 8 contacts the inner lower surface of the pallet P, that is, the upper surface of the lower deck board P2, and presses it. Before the fork 6 contacts the lower surface of the upper deck board P1 described above,
That is, the size and arrangement of each part of the pallet lock device 31 are set so that the lock member 34 is pivoted downward before the movable member 37 is displaced to the upper surface of the fork 6. Therefore, immediately after the tip of the lock bar 38 comes into contact with the upper surface of the lower deck board P2 and applies a pressing force thereto, the fork 6 contacts the upper deck board P1 and presses it. That is, in the state of FIG. 3b,
The fork 6 contacts the lower surface of the upper deck board P1 and presses it upward, and the lock bar 38 contacts the upper surface of the lower deck board P2 and presses it downward. Further, at this time, the spring 35 as an elastic member also has an effect of absorbing the variation when the vertical dimension of the hole Ph of the pallet P varies.

As a result, the pallet P is locked by the upward and downward pressing force from the inside thereof, and the pallet P is not easily detached from the fork 6. Even if the fork continues to rise, the state shown in FIG. 3b is maintained. Therefore, the pallet P is prevented from slipping, shifting, swinging, etc., and the load W on the pallet P does not collapse. It is kept stable without occurring.

When the movement of the load W by the forklift is completed and the load W is unloaded together with the pallet P on another ground or shelf, the pallet lock device 31 is operated by the pallet lock device 31 shown in FIGS. 3b to 3a.
The operation opposite to the above-mentioned case of the unloading is performed. That is, when the pallet P comes into contact with the above-mentioned shelf or the like and stops the lowering operation, the upper surface of the fork 6 is separated from the upper deck board P1 by the continuous lowering operation of the fork 6. Along with this, the lock member 34 also moves the spring 35.
The posture changes so as to turn upward, that is, in the clockwise direction in the drawing against the force of the above, and the center line 35a of the spring 35 traverses the turning shaft 33 of the lock member 34 from bottom to top in the middle of the turning. , Located above it. As a result, the spring 35 causes the lock member 34 to rotate about the shaft 33.
Urging upward, that is, reversing the direction of the urging force from the lower side to the upper side, the lock member 34 pivots upward and separates from the lower deck board P2, and the original state shown in FIG. Return to.

As a result, the pallet P is released from the locked state, and by moving the fork 6 rearward from this state, the fork 6 is separated from the pallet P and the unloading is completed. Therefore, according to the second embodiment described above, similarly to the first embodiment, the pallet P is firmly locked on the fork 6 from the loading operation to the unloading operation, and slips or swings. Does not occur. Further, the pallet locking operation in the unloading operation and the unloading operation does not require any manual work by an operator, and does not require a drive source such as a motor or a cylinder device or an electric means, and has a simple mechanism. Definitely done.

Also in the second embodiment, the movable member 37 and the lock bar 38 can be constructed as separate bodies. Also, pallet lock device 3
1 is provided on the lift bracket 4, it may be provided on the fork 6 as in the first embodiment described above. Further, in the second embodiment, the spring 35 is arranged so as to cross the shaft 33.
3 is provided on the left side of the pin 36b in the drawing, and the elastic force of the spring 35 acts not in the pulling direction but in the shortening direction, the same operation as in the second embodiment is performed. be able to. Although detailed description is omitted, in this case, the extension line of the spring 35 crosses the shaft 33.

Next, a third embodiment will be described with reference to FIGS. 4a and 4b. In addition, the above-mentioned first and second
As with the third embodiment, FIG. 1 is generally applicable to this third embodiment as well. Similarly, FIG.
Is a fork 6 in the hole Ph of the pallet P grounded on the ground or the like.
4b shows a state in which the fork 6 is inserted, and FIG. 4b shows a state in which the fork 6 is lifted from the state in FIG. 4a. Reference numeral 51, which is shown enlarged in the circle, is a pair of left and right pallet lock devices, which are arranged close to the inside of each fork 6.

The pallet lock device 51 includes a bracket 52 fixed to the inner surface of the bent portion of the fork 6, a movable member 57 rotatably supported on the bracket 52 by a shaft 71, and another shaft 72 on the bracket 52. And a first spring 73 stretched between the bracket 52 and the movable member 57.
And a second spring 74 stretched between the bracket 52 and the lock bar 58. A shaft 71 that supports the movable member 57 is provided at a position toward the rear of the vehicle body of the bracket 52, and a shaft 72 that supports the lock bar 58 is provided at a position toward the front of the vehicle body of the bracket 52. Further, the first spring 73 between the bracket 52 and the movable member 57 is located at the front-rear center of the bracket 52, and the second spring 74 between the bracket 52 and the lock bar 58 is the above-mentioned first spring. 73
They are arranged in front of the vehicle body side by side in a substantially vertical direction. Further, the upper end of the first spring 73 is engaged with the pin 75a fixed to the upper portion of the bracket 52, and the lower end thereof is engaged with the pin 75b fixed to the vehicle forward position from the shaft 71 of the movable member 57. To be done. Similarly, the upper end of the second spring 74 is engaged with a pin 76a fixed to the upper portion of the bracket 52, and the lower end thereof is engaged with a pin 76b fixed to a position rearward of the vehicle body from the shaft 72 of the lock bar 58. Are combined. The movable member 57 is formed in a substantially L shape from a pallet detection portion 57a extending forward of the vehicle body and a locking portion 57b extending downward from a rear portion of the vehicle body of the detection portion 57a, and an upper edge of the detection portion 57a is formed as described above. It abuts on a stopper 77 protruding from the bracket 52. A shaft 71 that supports the movable member 57 is provided in the locking portion 57b, and a pin 78 provided at the vehicle body rear portion of the lock bar 58 is in contact with the lower end of the locking portion 57b from below. .

In the state of FIG. 4a, the movable member 57 is
Is urged by the first spring 73 to rotate clockwise about the shaft 71 and is urged to rotate in the clockwise direction, and is stopped by the upper end edge of the detecting portion 57a contacting the stopper 77. The lock bar 58 is urged to rotate counterclockwise about the shaft 72 by the second spring 74, and is stopped by the pin 78 contacting the lower end of the locking portion 57b. This Figure 4
In the state of a, the movable member 57 is arranged so that the pallet detector 57a is parallel to the fork 6 and the detector 57a is located slightly above the upper surface of the fork 6 in a side view. It Similarly, FIG.
In the state of “a”, the lock bar 58 is arranged so as to be included in the vertical range of the fork 6 in a side view. Further, in this state, there is a clearance 62a between the movable member 57 and the upper deck board P1 of the pallet P.
However, the size and arrangement of each member are set so that a skimmer 62b is formed between the lock bar 58 and the lower deck board P2 of the pallet P. Therefore, when the fork 6 is inserted into the hole Ph of the pallet P, the pallet lock device 51 is smoothly inserted into the hole Ph without interfering with the pallet P.

Explaining an example of the unloading work, the insertion of the fork 6 into the pallet P is completed, and if the fork 6 is lifted from the state of FIG.
The relative height relationship with and changes, the upper clearance 62a is gradually smaller, and the lower clearance 62b is gradually larger. When the clearance 62a becomes zero and the movable member 57 comes into contact with the inner upper surface of the pallet P, that is, the lower surface of the upper deck board P1 forming the pallet P, the movable member 57 is contacted.
Rotates counterclockwise around the shaft 71 against the force of the first spring 73, and the locking portion 57a is displaced so as to escape to the upper right. Before the fork 6 contacts the lower surface of the upper deck board P1, that is, before the movable member 57 is displaced to the upper surface of the fork 6, the pin 78 disengages from the locking portion 57b, whereby the lock bar is released. 5
8 is rotated counterclockwise about the shaft 72 by the force of the second spring 74. The front end of the lock bar 58 on the front side of the vehicle body comes into contact with the upper surface of the lower deck board P2 of the pallet P and presses it downward, and immediately after that, as shown in FIG.
As shown in b, the upper surface of the fork 6 contacts the lower surface of the upper deck board P1 and presses it upward. At this time, the second spring 74 as an elastic member has an effect of absorbing the variation when the vertical dimension of the hole Ph of the pallet P has a variation.

As a result, the pallet P is locked by receiving upward and downward pressure from the inside thereof, and is in a state where it cannot be easily separated from the fork 6. Even if the fork continues to rise, the state shown in FIG. 4b is maintained. Therefore, the pallet P is prevented from slipping, shifting, swinging, etc., and the load W on the pallet P does not collapse. It is kept stable without occurring.

When the movement of the load W by the forklift is completed and the load W is unloaded together with the pallet P onto another ground or shelf, the pallet lock device 51 is operated by the pallet lock device 51 from FIG. 4b to FIG. 4a.
The operation opposite to the above-mentioned case of the unloading is performed. That is, when the pallet P comes into contact with the above-mentioned shelf or the like and stops the lowering operation, the upper surface of the fork 6 is separated from the upper deck board P1 by the continuous lowering operation of the fork 6. Along with this, the lock bar 58 also turns clockwise in the drawing against the force of the second spring 74, and accordingly, the movable member 57 also turns clockwise in the drawing by the force of the first spring 73. When the lock bar 58 returns to a state parallel to the fork 6 as shown in FIG. 4a, the pin 78 provided on the lock bar 58 causes the locking portion 57b of the movable member 57 to move.
After returning to the lower edge position, the pallet lock device 51 returns to the original state shown in FIG.
It becomes a state separated from.

As a result, the pallet P is released from the locked state, and by further moving the fork 6 rearward from this state, the fork 6 is separated from the pallet P and the unloading is completed. Therefore, according to the third embodiment described above, the pallet P is firmly locked on the fork 6 from the loading operation to the unloading operation, and does not slip or swing. Further, the pallet locking operation in the unloading operation and the unloading operation does not require any manual work by an operator, and does not require a drive source such as a motor or a cylinder device or an electric means, and has a simple mechanism. Definitely done.

Although three embodiments have been described above, the present invention is not limited to these as described above, and various modifications can be configured. For example, a switch that detects the turning movement of the movable member or the lock bar is provided, and the buzzer sounds or the lamp is turned on according to the output of this switch to notify the operator that the locking operation or the unlocking operation has been performed. This will be even more convenient. In addition, if the tip of the lock bar is long and parallel to the upper surface of the lower deck board when locked, the shape can be bent in advance so that it can be widely applied to the shape of the lower deck board.
For example, even if the lower deck board has holes or irregularities, the board can be contacted in a long range and can be reliably locked. Further, if the mounting position of each pallet locking device can be changed in the width direction of the fork so that the space between the pallet locking devices can be changed, the pallet hole position can be changed laterally. Furthermore, the tip portion of the lock bar may be bent downward to form a hook portion, and the hook portion may be engaged with a hole or the like formed in the lower deck board. These examples described here are extremely useful in the practice of the present invention and can be an important part of the present invention.

【The invention's effect】

As described above, according to the present invention, the pallet can be securely locked, so that the pallet does not slip on the fork, is not displaced, or rocks, and the pallet can be locked. It is possible to reliably prevent collapse of loads. Further, even when the fork is not tilted up and down, the pallet can be surely prevented from slipping, so that it can be widely used for carrying loads by a forklift and can be applied to a model in which the fork does not tilt. That is, the present invention is
The present invention can be applied not only to the reach-type forklifts described in each of the above-described embodiments but also to various forklifts, for example, a counter-type forklift and an order picking truck.

[Brief description of drawings]

FIG. 1 is a plan view showing an outline of a reach type forklift according to the present invention.

FIG. 2a is a side view (unlocked state) showing the first embodiment of the present invention.

FIG. 2b is a side view (locked state) showing the first embodiment of the present invention.

FIG. 3a is a side view (unlocked state) showing a second embodiment of the present invention.

FIG. 3b is a side view (locked state) showing the second embodiment of the present invention.

FIG. 4a is a side view (unlocked state) showing a third embodiment of the present invention.

FIG. 4b is a side view (locked state) showing the third embodiment of the present invention.

FIG. 5 is a side view of a reach type forklift.

[Explanation of reference numerals] 1 vehicle body 3 mast (elevating means) 4 lift bracket (load supporting means) 5 lift cylinder (elevating means) 6 fork (load supporting means) 11,31,51 pallet locking device 17,37,57 movable member 18, 38, 58 Lock bar 15, 35, 73, 74 Spring (elastic member) 19 Leaf spring (elastic member) 14, 34 Lock member P Pallet Ph Pallet hole P1 Upper deck board P2 Lower deck board W Load

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3F333 AA02 AB13 AE02 AE21 AE40                       AF08 FG03 FG07 FG10

Claims (8)

[Claims] 1. A load supporting means having a fork inserted into a pallet for placing a load and a lift bracket for supporting the fork, and an elevating means for raising and lowering the load supporting means. In a forklift,
The load supporting means is provided with a pallet locking device for locking the pallet inserted into the fork by pressing the inner lower surface of the pallet in association with the relative elevation of the fork with respect to the pallet. Forklift to do. 2. The pallet locking device releases the lock of the pallet in association with the relative lowering of the fork with respect to the pallet.
Forklift described in. 3. The pallet lock device includes a movable member that comes into contact with the pallet and is displaced when the pallet is raised, and a lock bar that presses the pallet in conjunction with the displacement of the movable member. The forklift according to claim 1 or 2. 4. The forklift according to claim 3, wherein the lock bar is provided with an elastic member for elastically pressing the pallet. 5. The movable member and the lock bar are both urged upward by a spring, and the movable member is urged by the spring so as to project from the upper surface of the fork and pressed downward by the pallet. 5. The forklift according to claim 3, wherein the forklift is displaced, and the lock bar moves downward against the spring as the movable member is displaced. 6. The movable member and the lock bar are formed integrally with each other, and the lock bar is moved downward by an amount corresponding to the movable member being pressed by the pallet and displaced downward. The forklift according to any one of claims 3 to 5, wherein the movable member presses an inner upper surface of the pallet and the lock bar presses an inner lower surface of the pallet. 7. The lock bar is supported so as to be vertically rotatable about an axis, and a spring is arranged between the lock bar and the load supporting means, and the spring is the spring or an extension line thereof. Is arranged so as to traverse the shaft as the lock bar turns, and the movable member operates so as to turn the lock bar downward when the movable member is displaced by being pressed by the pallet. The forklift according to any one of claims 3 to 5, wherein the forklift is provided. 8. The lock bar is urged downward by a spring, and the movable member is formed with a locking portion for restricting downward movement of the lock bar. 5. When the lock bar is displaced by being pressed by the pallet, the lock bar relaxes or releases the restriction by the locking portion and moves downward by the biasing force of the spring. Forklift truck.