JP2003267681A - Forklift truck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reach forklift truck that can tilt a load longitudinally without a lateral tilt even in an unbalanced load condition and can reduce manufacturing cost and maintenance cost. <P>SOLUTION: A reach carriage 6 supported for reciprocation on a vehicle body 1 supports a left and a right masts 8 for longitudinal tilt on fulcrum shafts 7 set at an intermediate height portion. A left and a right checking members 20 for bearing the left and right masts 8 below the fulcrum shafts 7 are mechanically synchronized by a synchronizing mechanism 26, and when driven by a single tilt cylinder 25 via the synchronizing mechanism 26, tilt the left and right masts 8 synchronously irrespective of a loaded condition. <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 truck.

[0002]

2. Description of the Related Art As shown in the side view of FIG. 9, for example, in a reach type forklift, a pair of left and right straddle arms 102 are provided at the front of a vehicle body 101, and the straddle arms 102 are rotatably attached at the front ends thereof. The supported road wheel 103 and the drive wheel 104 and casters 105 supported on the rear portion of the vehicle body 101 enable traveling.

A reach carriage 106 is supported on the lower part of the vehicle body 101 so as to be able to move forward and backward with the straddle arm 102 as a guide, and right and left masts 107 are vertically raised at the front end of the reach carriage 106. The masts 107 support lift brackets 108 that move up and down using these as guides.

Further, a fulcrum shaft 109 is supported on the upper portion of the lift bracket 108, and a tilt bar 110 integrated with a backrest is pivotally supported on the fulcrum shaft 109 so as to be tiltable back and forth. A pair of left and right forks 111 is provided on the front side of the so as to be tiltable about the fulcrum shaft 109.

The lift bracket 108 has a body 1
A tilt cylinder 112, which is a hydraulic cylinder, is supported at two symmetrical positions from the left and right center line of 01, and the tilt bar 110 is biased forward by the weight of the fork 111 and the tilt bar 110. The cylinder 112 is adapted to receive it from the rear.

When the tilt cylinders 112 forming a pair are extended synchronously with a hydraulic circuit, the tilt bars 110 are simultaneously extruded at two places, and the forks 111 are pulled.
Is tilted backward, that is, the mast 107 is tilted backward. Further, when these tilt cylinders 112 are synchronized and shortened by a hydraulic circuit, the tilt cylinders 112 are shortened.
Following the shortening, the tilt bar 110 and the fork 111 tilt in the forward tilt direction, that is, in the direction in which the mast 107 tilts forward.

[0007]

By the way, in the reach type forklift, the center of gravity of the load is shifted from the left and right centerlines of the vehicle body 101 and both forks 111, and the load is placed on the fork 111, and the load amount is evenly applied to both forks 111. In some cases, a so-called unbalanced load state is not shared, and in this case, for example, if the fork 111 is tilted backward, the extension speeds of the left and right tilt cylinders 112 may be different and the load may be tilted left and right.

When the load placed on the fork 111 tilts to the left or right, the load placed on the fork 111 comes into contact with another load or a building such as a building wall that is placed adjacent to the load. However, the measure is to place an appropriate gap between the cargo and the surrounding cargo and structures, but this measure limits the amount of luggage that can be accumulated in a cargo storage area of a certain area. Alternatively, there is a problem that a wide cargo storage area is required to accumulate a predetermined amount of cargo.

The present invention solves the problems of the prior art,
An object of the present invention is to provide a reach-type forklift truck that can lean the load forward and backward without leaning left and right even in an unbalanced load state, and can reduce manufacturing costs and maintenance costs.

[0010]

In order to achieve this object, a forklift according to the present invention (hereinafter, simply referred to as the present invention) has left and right masts on a vehicle body via a fulcrum shaft at a predetermined height of each mast. And a pair of left and right restraining members that are pivotally supported so as to be tiltable back and forth, individually receive each mast at a position separated upward or downward from the fulcrum shaft, and control the angle of each mast by rotating or moving back and forth. And a tilt mechanism that mechanically synchronizes both the restraining members and one tilt cylinder that drives both restraining members via the synchronizing mechanism.

According to this, since the left and right restraining members control the angles of the left and right masts in a mechanically synchronized manner, the mast, the tilt bar and the fork are not affected even if the loads shared by the respective restraining members are uneven. Since the right and left tilts are synchronized, the cargo does not tilt left and right.

Since there is only one tilt cylinder,
The hydraulic piping is simplified, and the manufacturing cost and maintenance cost can be reduced.

Incidentally, in the present invention, even if the left and right masts are fixed in height, for example, each mast is provided with an outer mast supported by the vehicle body and an inner mast that is raised and lowered by using the outer mast as a guide. The height of the inner mast may be expanded and contracted by moving up and down synchronously.

Each mast may be supported by a frame of the vehicle body or a component fixed to the frame via left and right fulcrum shafts,
Alternatively, it may be supported via a component such as a reach carriage that is capable of moving forward and backward with respect to the frame of the vehicle body.

By the way, when the mast is supported on the vehicle body so as to be tiltable back and forth via the fulcrum shaft, the fulcrum shaft is supported by the weight of the mast, the lift bracket and the fork, regardless of the position of the mast in the height direction. A rotational force in the forward tilting direction, that is, in the direction in which the mast is tilted forward is generated.

Therefore, the mast may be pivotally supported on the vehicle body at any position in the height direction, but at a position higher than the height at which the check member can be arranged below the fulcrum shaft and lower than the vehicle body height. It is preferred to support the mast.

It is not preferable to pivotally support the mast at a position higher than the height of the vehicle body because the cost, the weight of the vehicle body and the like increase remarkably and the vehicle body weight also increases. Also, for example, in order to prevent the fork up and down on the front side of the mast from being hindered, it is necessary to pivotally support the vehicle body at such a low position that the check member cannot be arranged below the fulcrum shaft, such as the lower end of the mast. Therefore, it is necessary to provide a restraint member so as to restrain the mast from the front, which is not preferable because the structure becomes complicated. In particular, in the reach type forklift, in addition to the complicated structure, it is necessary to dispose the synchronization mechanism behind the lift cylinder that moves up and down the mast and the lift bracket, so that the stroke of the reach carriage is narrowed. It is not preferable because it occurs.

The restraint means of the present invention restrains the forward inclination of the mast by receiving the rotational force of the mast around the fulcrum axis, and the restraint member of the present invention has a height for individually receiving the left and right masts. May be above or below the fulcrum axis.

However, when the mast is received above the fulcrum shaft, it is necessary to restrain the mast from the front so as not to prevent the fork and the backrest on the front side of the mast from moving up and down. A stop must be attached to each mast.

Further, in this case, when the left and right restraining members are provided on both the left and right outer sides of the mast, it is necessary to provide a synchronizing mechanism for mechanically synchronizing the left and right restraining members over the rear side and the left and right outer sides of the mast. Yes, the structure of the synchronization mechanism becomes complicated.

Particularly in the case of a reach type forklift, the portion of the synchronizing mechanism arranged behind the synchronizing mechanism mast hinders the backward movement of the reach carriage and the mast, and the reach stroke of the fork is narrowed.

When the mast is to be received below the fulcrum axis, the rear surface of the mast may be directly received by the restraint member, and it is not necessary to provide a stop that is specifically received by the restraint member.

Particularly, when the restraint member is arranged so as to receive near the lower end of the mast, the distance from the fulcrum shaft to the restraint member increases, and the load received by the restraint member can be reduced, which is preferable. In a forklift truck, it is more preferable because both the restraint members, the synchronizing mechanism and the tilt cylinder can be incorporated inside the reach carriage.

The distance between the fulcrum shaft and the position at which each restraint member receives the mast may be large or small. When this distance is large, the load received by each check member is small, but it is necessary to increase the lift amount or stroke of each check member. When this distance is small, the lift amount or stroke of each check member is reduced. Although it can be made small, the load received by each check member becomes heavy.

Further, in the present invention, each restraint member is composed of a movable member which receives the mast and moves the mast forward and backward.

For example, a circumferential cam such as an eccentric cam or an eccentric shaft is provided so as to be rotatable around a rotation axis, and a front-back distance between a contact point for receiving the mast of the restraining member and the rotation axis is set. A member that increases or decreases depending on the rotation phase of the restraint member can be adopted as the restraint member.

In this case, the rotational axes of the left and right restraining members are
For example, it may be something other than the horizontal axis such as the vertical axis or the front-back axis, but in order to simplify the overall configuration,
It is preferable that they have a common left and right axis.

Further, in the check member having the eccentric shaft,
A rotary bearing is externally fitted to the eccentric shaft and the mast is restrained on the outer peripheral surface of the rotary bearing, or a roller is externally fitted to the eccentric shaft via the rotary bearing and the mast is restrained on the outer peripheral surface of the roller. Therefore, it is preferable to significantly reduce the resistance at the contact point against the rotation of the restraint member.

As the restraint member for advancing and retracting the mast in the front-rear direction while receiving the mast, other members such as pistons, plungers, rods and the like that can be retracted in the front-rear direction can be adopted.

The synchronizing mechanism is not particularly limited as long as it mechanically synchronizes the left and right restraining members. For example, the synchronizing mechanism is supported by the vehicle body so as to be rotatable about the left and right axis, and the tilt cylinder and the both restraining members are mechanically supported. Some have a rotating shaft that is mechanically linked.

Here, the structure in which the tilt cylinder and the rotary shaft are interlocked is not particularly limited, and for example, a structure in which the rack that advances and retreats by the tilt cylinder and the pinion fixed to the rotary shaft or one of the check members is meshed is adopted. be able to.

As a structure for interlocking the tilt cylinder and the rotary shaft, the rotary shaft is constituted by a crank shaft, and the piston rod of the tilt cylinder rotatably supported by the vehicle body by trunnion support or clevis support is used as a crank pin. It is also possible to employ a structure in which the rotary shaft is formed of a crank shaft, and a piston rod of a tilt cylinder fixedly supported on the vehicle body is connected to a crank pin of the rotary shaft by a connecting rod.

In addition to these, as a structure for interlocking the tilt cylinder and the rotary shaft, an arm or a forked fork extending in the radial direction is fixed to the rotary shaft or one check member, and the free end of the arm or fork is fixed. A structure in which the portion is pushed and pulled by a tilt cylinder may be adopted.

The structure in which the left and right restraint members are mechanically interlocked with the rotary shaft is not particularly limited, either, but both restraint members are directly connected to each other at both ends of the rotary shaft so that they cannot rotate relative to each other, the rotary shaft and the respective restraint members. There is a structure in which a mechanical transmission mechanism is interposed between and.

However, it is possible to surely synchronize the two restraint members without causing any looseness between them.
In order to simplify the configuration, reduce the cost, reduce the size, and reduce the size, it is preferable to adopt a structure in which both the check members are directly connected to the rotation shaft such that they cannot rotate relative to each other.

Examples of the structure for directly fixing the two restraint members to the rotation shaft so that they cannot rotate relative to each other include, for example, a structure in which both the check members are fitted to both ends of the rotation shaft by keys, splines, serrations, etc. so that they cannot rotate relative to each other. A structure in which both check members are blindly fitted to both ends of the shaft, tightly fitted such as interference fit, shrink fit, etc., so that they cannot rotate relative to each other, both check members are screwed to both ends of the rotary shaft, and fixed by welding, etc. Structure,
There is a structure in which these are used together.

The mechanical transmission mechanism interposed between the rotary shaft and each check member is not particularly limited as long as it is configured to mechanically transmit the rotation of the rotary shaft to the check member. It is possible to employ a pinion mechanism, a gear transmission mechanism including a gear train, a belt transmission mechanism, a chain transmission mechanism, a slider / crank mechanism, a link mechanism including a link plate, a link rod, etc., an arm, a forked fork, and the like.

When a member which is provided so as to be able to move forward and backward is adopted as the restraint member, a synchronizing means having a slider which is supported by the vehicle body so as to be able to move forward and backward and which supports both restraint members so that they cannot move relative to each other is adopted. It is sufficient to drive this slider with one tilt cylinder.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION A forklift according to an embodiment of the present invention will be described below in detail with reference to the drawings. In the drawings, FIG. 1 is a principle view of the operation of a main part of a forklift according to an embodiment of the present invention, and FIG. 2 is a side view of the entire forklift.

The forklift truck shown in FIG. 2 is a reach type forklift truck, which is provided with a pair of left and right straddle arms 2 at the front portion of the vehicle body 1, and a road wheel 3 provided at the front end portions of these saddle arms 2 and the vehicle body 1. The drive wheels 4 and the casters 5 allow the vehicle to travel.

A reach carriage 6 is supported on the straddle arm 2 so as to be movable back and forth, and a left and right mast 8 is supported on the reach carriage 6 via a fulcrum shaft 7 so as to be tiltable forward and backward. A lift bracket 9 that moves up and down with these as guides is supported on the left and right masts 8. Further, a backrest 10 is attached to the lift bracket 9.
And the fork 11 are supported.

FIG. 3 is a vertical cross-sectional side view of a main part of the forklift truck. As shown in FIG. 3, the reach carriage 6 includes a carriage frame 12 formed in an L shape in a side view and a lower portion 13 thereof. Guide rollers 14 are rotatably supported on the left and right sides at appropriate intervals in the front-rear direction.

FIG. 4 is a plan view of the entire forklift truck. As shown in FIG. 3 and FIG. 4, the inner surface of the straddle arm 2 is a groove-shaped guide rail 1 which is open to the inside.
5, the guide rollers 14 of the carriage frame 12 are rotatably thrust into the guide rails 15 so that the reach carriage 6 moves forward and backward with the guide rails 15 as a guide.

Further, as shown in FIG. 4, the reach cylinder 1 composed of one hydraulic cylinder is mounted on the frame 16 of the vehicle body 1.
7 is supported, and the reach carriage 12 is moved forward and backward by the reach cylinder 17.

As shown in FIG. 3, the fulcrum shaft 7 fixed to the intermediate height of the mast 8 is provided on the upper end of the rising portion 18 which is erected from the front end of the lower portion 13 of the carriage frame 12, for example, metal. Is rotatably fitted in via a rotary bearing 19 made of
The backrest 10 and the forks 11 are biased by their own weights in the forward tilting direction about the fulcrum shaft 7, that is, in the direction in which the mast 7 tilts forward.

As shown in FIG. 4, the left and right masts 8 are provided with an outer mast 8a which is supported by the carriage frame 12 via a fulcrum shaft 7, and an inner mast 8b which moves up and down with the outer mast 8a as a guide. As shown in FIG. 2, the upper end portions of the outer mast 8a and the upper end portions of the inner mast 8b are roughly connected to each other by connecting frames 8c and 8d.

As shown in FIG. 4, below the fulcrum shaft 7,
That is, on the front portion of the lower portion 13 of the carriage frame 12, a check member 20 that receives the lower portions of the left and right outer masts 8a from the rear is rotatably supported around a common left and right axis.

As shown in FIGS. 1 and 3, each check member 2
Reference numeral 0 denotes an eccentric shaft 21 that is eccentric from the rotary shaft center O, and a rotary bearing 22 made of a bush (metal) on the eccentric shaft 21.
And a roller 23 that is rotatably fitted to the outer periphery of the outer mast 8a.

A liner 24 made of a wear-resistant material is attached to the lower portion of each outer mast 8a so as to prevent wear, and the liner 24 is brought into contact with the roller 23.

As shown in FIGS. 1, 3 and 4, the left and right restraining members 20 are disposed inside the rising portion 18 of the carriage frame 12, and the connecting reinforcing frame 29 of the lower portion 13 of the carriage frame 12 is arranged. Tilt cylinder 25 consisting of a single-acting hydraulic cylinder pivotally supported by a clevis 30
Are mechanically synchronized with each other via a synchronization mechanism 26.

That is, FIG. 5 is a vertical sectional front view of the synchronizing mechanism 26. As shown in FIG. 4 and FIG. 5, both ends of the synchronizing mechanism 26 are left and right at an intermediate height portion of the left and right rising portions 18. A rotary shaft 27 rotatably supported around the shaft center and a torque arm 28 whose base end is fitted to the rotary shaft 27 so as to be relatively non-rotatable by using a key, for example, are provided at both ends of the rotary shaft 27. The restraint member 20 is fitted onto each of the parts so as to be relatively non-rotatable by using, for example, a key.

The free end of the torque arm 28 is
The piston rods of the tilt cylinder 25 are connected to each other, and when the tilt cylinder 25 is shortened by tan, both the restraining members 20 rotate mechanically in synchronization, and the restraining member 20 and the liner 24 come into contact with each other as shown in FIG. The front-rear distance between the contact P and the rotation axis O of the check member 20 is rs to rl.
Then, the lower part of the mast 8 (outer mast 8a) is pushed forward, and the mast 8, the lift bracket 9, the backrest 10, and the fork 11 tilt backward.

As described above, the mast 8 is biased in the forward tilting direction so that the lower end portion thereof is always the roller 2 of each restraining member 20.
Since the tilt cylinder 25 extends, the check member 20 rotates in the direction in which the distance between the contact point P and the rotation axis O decreases, and the mast 8 follows the rotation of the check member 20. The lower portion of the mast moves forward and backward, whereby the mast 8, the lift bracket 9, the backrest 10, and the fork 11 tilt forward about the fulcrum shaft 7.

Here, the left and right restraining members 20 rotate mechanically in synchronism to move the lower parts of the left and right masts 8 forward and backward, so that they are related to the rotational force of the mast 8 received by the left and right restraining members 20. It is driven without synchronization. That is, since the left and right forks 11 tilt forward and backward without slowing each other even if the left and right forks 11 share different load loads, the left and right forks 11 can be tilted forward and backward without tilting left and right.

Since the loads can be tilted back and forth without being tilted to the left and right, the space between the loads in the loading place can be narrowed, the area of the loading place can be reduced, and a large amount can be stored in the loading place of a predetermined area. You will be able to collect your luggage.

Further, according to this forklift truck, since one tilt cylinder 25 is used, the construction of the hydraulic circuit becomes simpler than the conventional forklift truck using two tilt cylinders, and the cost of parts and hydraulic piping work are reduced. The manufacturing cost including the cost can be significantly reduced, the maintenance can be simplified, and the maintenance cost can be reduced.

Particularly, in this embodiment, the tilt cylinder 2
Since 5 is composed of a single-acting hydraulic cylinder, the structure of the hydraulic circuit can be further simplified, the manufacturing cost can be further reduced significantly, and the maintenance can be further simplified, thereby significantly reducing the maintenance cost. it can.

The difference between the loads shared by the left and right forks 11 is the contact pressure between the lower portion of the outer mast 8a and the roller 23, the contact pressure between the roller 23 and the bush 22, the contact pressure between the bush 22 and the eccentric shaft 21, and the like. Although the difference affects the wear of these parts, the progress of the wear is slow and the heavy load is not always applied to only one of the forks 11. Therefore, this wear difference can be practically ignored. . If the rotary shaft 27 is designed so that its torsional rigidity is sufficiently high,
Twisting of the rotary shaft 27 does not slow down the tilting of the fork 9.

FIG. 6 is a vertical sectional side view of a main portion of a forklift according to another embodiment of the present invention. As shown in FIG. 6, in this forklift, a rotary shaft of a synchronizing mechanism 26 is provided at a lower portion 13 of a carriage frame 12. 27 is rotatably supported, and the check member 20 is supported inside the lower portion 13 at both ends of the rotary shaft 27 so as not to be rotatable relative to each other.

The restraint member 20 has a crank arm 31 whose one end is fitted onto the rotary shaft 27 such that the rotary shaft 27 cannot rotate relative to the rotary shaft 27, and an eccentric shaft 21 connected to the tip of the crank arm 31.
The eccentric shaft 21 is provided with a rotary bearing 22 fitted on the outside, and the rotary bearing 22 receives the liner 24 of the mast 8.

The tilt cylinder 25 is arranged in the lower portion 13 of the carriage frame 12 and is supported by the trunnion on the lower portion 13.

According to this, since the check member 20 receives the mast 8 at a position far away from the fulcrum shaft 7, the mast 9
The contact pressure between the restraining member 20 and
Since the resistance to the rotation of is reduced, the load of the tilt cylinder 25 is reduced.

Other constitutions, operations and effects of this embodiment are the same as those of the above-mentioned embodiment of the present invention.

FIG. 7 is a vertical sectional side view of a main part of a forklift according to another embodiment of the present invention. As shown in FIG. 7, the restraining member 20 of the forklift is composed of a cam.

Other constitutions, functions and effects of this embodiment are the same as those of the previous example.

FIG. 8 is a vertical cross-sectional side view of a main part of a forklift according to still another embodiment of the present invention. In this forklift, a pair of left and right extending in the front-rear direction is provided on the inner surface of the lower portion 13 of the carriage frame 12. A guide rail 32 is provided.

A slide bearing 33, which forms a front-rear pair, is slidably fitted to each guide rail 32 with a proper space in the front-rear direction, and the slide bearing 33 is fixed to a slider 34 on a common plate frame. is doing.

At the front edge of the slider 34, check members 20 for individually receiving the liners 24 fixed to the rear surfaces of the lower ends of the left and right masts 8 are fixed at right and left sides with appropriate intervals. By extending the tilt cylinder 25 fixed to the rear wall 35 of the carriage frame 12, the left and right masts 8 are mechanically synchronized and tilted backward, and by shortening the tilt cylinder 25, the left and right masts 8 are mechanically moved. I try to lean forward synchronously.

That is, this forklift synchronization mechanism 26
Is composed of the left and right guide rails 32, a pair of left and right slide bearings 33 and a slider 34, which are paired in the front and rear direction.

In this embodiment, the restraint member 20 is
Roller 23 for rolling contact with liner 24 and this roller 2
3 is provided with a bracket 37 that rotatably supports the rotary bearing 22 and the shaft 36, but the structure of the restraint member 20 is not limited to this. For example, one restraint member is used for each restraint member. 20 may be configured.

Although each restraining member 20 is positioned and fixed to the slider 34 by using bolts, nuts and pins, the restraining member 20 may be fixed to the slider 34 by another method such as welding.

Other constitutions, operations and effects of this embodiment are the same as those of the above-mentioned embodiments.

[0073]

As described above, in the reach type forklift of the present invention, the left and right masts are pivotally supported on the vehicle body so as to be tiltable back and forth via the fulcrum shaft at a predetermined height of each mast.
The masts are mechanically synchronized with a pair of left and right restraint members that individually receive the masts at positions separated upward or downward from the fulcrum shaft and control the angle of each mast by rotating or moving forward and backward. The present invention is characterized in that a synchronizing mechanism for making it possible and one tilt cylinder for driving both check members through the synchronizing mechanism are provided.

According to this, the angle of the left and right masts is controlled by the check member that mechanically synchronizes, and the left and right forks can be synchronously tilted back and forth regardless of the load shared by the left and right forks. Is obtained.

By this action, the cargo can be tilted back and forth without being tilted to the left and right, and the left-right space of the cargo in the cargo storage area can be narrowed, so that a larger amount of cargo can be accumulated in the cargo storage area than before. Alternatively, it is possible to obtain an effect that the area of the cargo storage area for accumulating a predetermined amount of cargo can be reduced.

Since there is only one tilt cylinder,
Compared with the conventional forklift truck that uses two tilt cylinders, the hydraulic circuit configuration is simpler, the manufacturing cost including parts cost and piping work cost can be significantly reduced, and the maintenance is easy. The effect that the maintenance cost can be reduced can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the operating principle of the present invention.

FIG. 2 is a side view of the present invention.

FIG. 3 is a vertical side view of the present invention.

FIG. 4 is a plan view of the present invention.

FIG. 5 is a vertical sectional front view of the present invention.

FIG. 6 is a vertical side view of the present invention.

FIG. 7 is a vertical side view of the present invention.

FIG. 8 is a vertical side view of the present invention.

FIG. 9 is a side view of a conventional example.

[Explanation of symbols]

1 car body 6 reach carriage 7 fulcrum axis 8 masts 20 Check members 19 spindle 20 eccentric shaft 21 rotary bearing 24 Synchronization mechanism 25 tilt cylinder 26 rotation axis

Claims (5)

[Claims] 1. A left and right mast is pivotally supported on a vehicle body so as to be tiltable forward and backward through a fulcrum shaft at a predetermined height of each mast, and each mast is individually located at a position separated upward or downward from the fulcrum shaft. A pair of left and right check members that control the angle of each mast by receiving, rotating, or moving back and forth, a synchronization mechanism that mechanically synchronizes both check members, and both check members are driven through this synchronization mechanism. A forklift characterized by being provided with one tilt cylinder. 2. A reach carriage that is supported on a vehicle body so as to be able to move forward and backward is provided, the mast is supported on the reach carriage so as to be tiltable forward and backward through the fulcrum shaft, and the restraining member is provided inside the reach carriage. The forklift according to claim 1, wherein a synchronizing means and a tilt cylinder are arranged. 3. Each check member is rotatably provided around a common rotation axis, and a front-back distance between a contact point for receiving the mast of the check member and the rotation axis is a rotational phase of the check member. The forklift according to claim 1 or 2, wherein the forklift is increased or decreased by. 4. The synchronous mechanism is rotatably supported on the vehicle body about a left-right axis and has a rotary shaft mechanically interlocked with the tilt cylinder and both restraining members. Forklift according to item 3. 5. The forklift according to claim 1, wherein the synchronizing mechanism is supported by the vehicle body so as to be movable in the front-rear direction, and is composed of a slider that is driven by a tilt cylinder and supports both check members.