JPH0610077B2 - Brake for cargo lifting device - Google Patents

Description

Description: [Industrial application] The present invention relates to a brake suitable for a rotary drive type cargo lifting device.

[Prior Art] In a cargo lifting device of a system in which a drive source such as a motor rotates a shaft, and the cargo is lifted by being converted into a linear (elevating) motion by its rotational motion or a screw (screw) or rack and pinion, The brakes that stop or brake the descent of the cargo are usually located on that axis. As a general axis brake, an electromagnetic type is known that operates in conjunction with the stop of the drive source, but a non-stationary cargo lifting device is often a manual brake. Has been done. In the case of non-stationary devices where the place of use is not constant, there is often no choice but to rely on battery power, so low power consumption is required,
In addition, the manual method is preferred because it has no failure.

Also in the cargo lifting device of Japanese Patent Publication No. 52-18970, a manual type is used, which brakes the lifting of the cargo and acts on the rotating shaft. The device of the publication is
A device suitable for cargo transportation including loading and unloading from trucks and climbing stairs. A screw shaft connected to a motor as a drive source is laid vertically (up and down) on a frame with wheels. An elevating frame having a nut member and a cargo supporting member that are screwed together is assembled so as to be vertically movable along the frame with wheels. The lifting of the cargo, that is, the lifting frame is performed based on the rotation of the screw shaft, and the braking is performed by the frictional force of the manual brake with respect to the screw shaft.

FIG. 7 shows the brake described in the above publication and is a brake drum provided integrally with the above-mentioned screw shaft 4 '.
A brake band (strap) 10 'is wound around 30' as a friction member, and a braking force adjustment consisting of a link 21 ', a bolt 25', a handle 23 ', etc., between its end and the frame 2'with wheels. Equipped with means 20 '. By turning the handle 23 'and pulling the bolt 25' to the right in the figure,
The link 21 'is displaced around the pivot 21a' and the band 10 'is tightened on the surface of the drum 30', and a considerable braking force is applied to the drum 30 ', that is, the shaft 4'. According to the same publication, in order to keep the cargo at a certain height when the motor is not started, and to prevent the cargo from dropping suddenly when lowering the cargo, the brake 10 moves the band 10 'depending on the rotating position of the handle 23'. The braking force to be applied should be adjusted in advance so that it is as strong as the weight of the cargo, and the braking force should be constantly applied to the shaft 4 '. When the motor is stopped, the cargo is supported by the braking force of the brake, and when the motor is started with a certain force or more, the shaft rotates to lift and lower the cargo.

[Problems to be Solved by the Invention] As described above, the manual brake in the rotary drive type cargo lifting device adopts a method in which the friction member constantly applies the braking force of the set strength to the shaft. , The conventional brakes have the following problems.

B) Since the braking force always acts on the shaft, in order to raise the cargo, a large output corresponding to the sum of the weight of the cargo and the above braking force is required for the drive source (motor etc.) It is wasteful in terms of specifications and energy consumption. The reason why the brake is always applied is that the drive source is usually started and stopped frequently during lifting and lowering work of the cargo, while the manual brake is released and activated accordingly. Because it is difficult. However, increasing the specifications of the equipment increases the cost of the lifting device, and it may be difficult to handle due to the increase in weight. Also, if the energy consumption of the drive source is large, the energy consumption of the same energy source (battery etc.) Considering the fact that the maximum amount of work in one operation is small, it can be said that the task of b) is not negligible.

B) Although a means for adjusting the braking force is provided, it is practically impossible to increase the braking force instantaneously, for example, because the handle (reference numeral 23 'in FIG. 7) must be rapidly rotated. For this reason, the braking force should be set larger than the cargo weight so that the cargo does not drop when the drive source is stopped. On the other hand, when lowering the cargo, a force equivalent to the difference between the braking force and the cargo weight is required as the output of the drive source. , Careful adjustment is essential so that it fits within a narrow range, not less than the cargo weight.

It is an object of the present invention to provide a brake in which the braking force hardly acts on the shaft when raising a cargo, thereby lowering the required output per drive source of the cargo lifting device and reducing energy consumption. Further, in the present invention (claim 2), it is also possible to stop the cargo suddenly by applying sudden braking, and therefore, there is also provided a brake capable of easily setting the braking force in advance.

[Means for Solving the Problem] The cargo lifting / lowering device brake of the present invention (claim 1) is of a type in which the rotation of the shaft for lifting the cargo lifting / lowering member is braked by a friction member (for example, a brake band or shoe). In the case of a brake, a surface to be braked by pressing a friction member is formed on the surface of a member to be braked (for example, a brake drum or a disc rotor) that can rotate separately from the shaft,
Between the member to be braked and the shaft, one-way transmission means (for example, ratchet or various one-way clutches) for transmitting only the rotation of the shaft when the cargo support member descends to the member to be braked is provided.

As described in claim 2, in the above-mentioned brake, a brake drum is used as the braked member, a brake band is wound around the brake member as the friction member, and one end of the band is pulled to brake the drum. ,
A lever that is operated from the movable end position to one side, connects one end of the band and the lever, and a pair of engaging members with a play when the lever is in the movable end position, so as to generate elastic force in the direction of pulling the band , A spring interposed between the lever and the band, and an operating means having a spring deflection setting piece capable of adjusting the elastic force of the spring when the lever is at the movable end position, at one end of the band. It may be provided by connecting.

[Operation] In the cargo lifting device, the brake of the present invention provided on the shaft connected to the drive source is usually used in a state where the friction member is always pressed against the surface of the member to be braked. Bring

1) Keeping the cargo at a certain height: In the lifting device, even if the drive source is stopped, a rotational force that lowers the cargo support member acts on the shaft based on the weight of the cargo, but with this brake, The rotation of the shaft in that direction is transmitted to the member to be braked through the one-way transmission means, and is braked by the friction member pressed against the surface thereof. Therefore, if the braking force is adjusted to a proper strength in advance, the brake keeps the cargo and the supporting member at a constant height.

2) To suppress the descent speed of the cargo: As in 1) above, the rotation of the shaft is transmitted to the member to be braked for braking, but when the braking force by the friction member is slightly small when the drive source is stopped or the worker When pushing the cargo support member downward, or when the drive source is started to lower the support member,
The downward force exceeds the braking force, and the cargo (and the supporting member) slowly descends due to the force substantially corresponding to the difference between the two.

3) Do not brake when the cargo is lifted: In the lifting device, the shaft is rotated by the drive source in the direction to lift the cargo support member, but due to the one-way transmission means, rotation in that direction is not supported. Since it is not transmitted to the braking member, the shaft (and hence the drive source) does not receive the braking force due to the friction member, even though the friction member is pressed against the member. In other words, this 3) is a point that is largely different from the conventional brake (see FIG. 7), and brings advantages in terms of the required output of the drive source and energy consumption.

The brake according to claim 2 has the above-mentioned 1), 2), and a brake band tightened on the surface of the brake drum.
It has the function of 3), but it is related to 4) below.
And the effect of 5) are also realized. 4) Adjustment of braking force strength: In this brake, the elastic force of the spring is normally transmitted to the engaging member so that the lever comes to the movable end position and the brake band is attracted toward the lever. To be In this state, since the engaging member has a play, the band is attracted by the elastic force of the spring regardless of the rigidity of the member. The band is tightened to the surface of the brake drum by this attracting force to generate a braking force, so the strength of the braking force can be adjusted by arbitrarily setting the spring deflection by the setting piece and determining the elastic force. It is possible.

5) Sudden braking for lifting and lowering cargo: Normally, when the lever at the movable end position is operated to one side,
First, the spring expands and contracts so that the engagement member has zero play.After that, the operating force of the lever is reduced by the rigidity between the band and the lever due to the engagement member without the elastic force of the spring. Informed to the band. In other words, if the lever is rapidly operated, after a moment, the cargo can be suddenly braked up and down by a strong braking force not via the spring. Therefore, the strength of the braking force adjusted in advance may be slightly lower than the weight of the cargo, and the strictness of the prior braking force adjustment is not required.

[Embodiment] An embodiment of the present invention is shown in FIGS. FIG. 1, FIG. 2, and FIG. 3 are a front sectional view, a plan view, and a plan sectional view, respectively, of a brake for a cargo lifting device. 4 (a) and 4 (b) are a front view and a side sectional view of a cargo carrier equipped with its brake as a cargo lifting device.

The freight carrier 1 shown in FIG. 4 has a lifting frame 3 incorporated in a carrying frame 2 with wheels 2a, and is the same as the device described in the above-mentioned publication (Japanese Patent Publication No. 52-18970). It is a device used for transportation (especially transportation involving lifting and lowering). The cargo A is placed on the cargo support member 3a integrally formed with the frame 3, and the worker pushes (or pulls) the carrier 1 while rolling the wheels 2a to convey the cargo A. By moving the lifting frame 3 up and down, the cargo A can be lifted for loading and unloading on a truck. As a structure for vertically moving the frame 3 with respect to the frame 2, a motor 5 as a drive source is attached to the frame 2, and a screw shaft 4 connected to the motor 5 is vertically mounted on the frame 2 via an upper bearing 4a. It has been passed. The elevating frame 3 is incorporated so as to slide up and down with respect to the frame 2, and since it integrally has a nut member 3b that is screwed into the threaded portion of the shaft 4, it moves up and down as the shaft 4 is rotated by the motor 5. To do. The entire usage of the carrier 1 for carrying the cargo is the same as the device of the above-mentioned publication including the procedure of loading and unloading the cargo A onto the truck and going up and down the stairs (the description here is Omitted).

While the motor 5 is activated by the battery 6 attached to the frame 2 to move the cargo A up and down, the carrier 1 is used to brake the cargo A (that is, the lifting frame 3) when the motor 5 is stopped. Has a characteristic brake 8 shown in FIGS. 1 to 3. Brake 8
Is a band brake that applies a braking force to the output shaft 5a of the motor 5 and the screw shaft 4 connected to the output shaft 5a, and is configured as follows.

a) First, as shown in FIG. 1, an inner cylinder portion 41b connecting the end 4a of the screw shaft 4 to the output shaft 5a of the motor 5 via the key 41a,
The transmission body 41 integrally formed with the outer edge portion 41c protruding outward at the lower portion thereof was fitted over both the end portion 4a and the output shaft 5a.

b) The cylindrical brake drum 30 is fitted into the inner cylinder portion 41b of the transmission body 41 such that the brake drum 30 can be relatively rotated by sliding. The drum 30 is a member to be braked that is braked by a brake band 10 described later, and has ratchet teeth 46 shown in FIG.

c) Near the outer edge portion 41c of the transmission body 41, the claw 4 shown in FIG.
4, the bolt 43 is swingably attached to the fulcrum, and by engaging with the leaf spring 45 provided on the outer edge portion 41c,
The tip 44a of the claw 44 was engaged with the ratchet teeth 46 of the drum 30. Since the claw 44 cannot be swung counterclockwise from the state of being engaged with the teeth 46, the above members (whose reference numerals are in the 40s) collectively function as the one-way transmission means 40. That is, by the action of these members, the rotational force thereof is transmitted to the drum 30 via the teeth 46 only when the transmission body 41 rotates counterclockwise in the figure with the screw shaft 4, that is, when the frame 3 descends.

d) As a friction member for braking the drum 30, as shown in FIG. 2, a brake band in which a metal band 10a is provided with a liner 10b.
10 was wound around the outer peripheral surface of the drum 30 and connected to the operating means 20 described in e) below.

e) The pins 21a and 21b attached to both ends of the band 10 are connected by the link plate 21c, and one pin 21b is connected to a pair of engaging members, that is, the bracket 22, the nut 23, and the butterfly bolt 25.
It was connected to the operation lever 27 via. Further, as shown in FIG. 1, a collar 23a is provided at the rear end portion (left end in the figure) of the nut 23.
Then, the coil spring 24 was compressed and mounted between it and the tip 22a of the bracket 22. On the other hand, lever 27
Is made swingable around a support shaft 27a provided on the above-mentioned carrying frame 2 (see FIG. 4), and is attached to the stopper 28 integrated with the frame 2 as shown in FIG. 1 as the movable end position. The operation means 20 thus configured has the following functions.

That is, the nut 23 has a gap between its tip (right end in the figure) 23b and the tip 22a of the bracket 22 in a normal state where the lever 27 hits the stopper 28-that is, the pin 21b.
・ As the engaging member between the levers 27 has a play, it is screwed into the threaded portion of the wing bolt 25, and the brim 23a cannot rotate inside the bracket 22. The screwing position of changes. In other words, when the lever 27 is at the movable end position, if you turn the butterfly bolt 25 while holding the head 25a, the nut 23 along with the brim 23a that is a deflection (compression amount) setting piece of the spring 24 (left and right in the figure). ), And the elastic force of the spring 24 is changed, so that the tightening force of the brake band 10 (that is, the braking force of the brake 8) in the normal state is adjusted. Also, when pulling the lever 27 (tilting it to the right in FIG. 4), the spring 24 is further contracted by the amount of the above-mentioned play, and then the nut 23
The front end portion 23b of the bracket abuts on the front end portion 22a of the bracket 22, and thereafter, the force for operating the lever 27 is transmitted to the pin 21b as it is and becomes the braking force of the band 10.

In the brake 8 configured as described above, by rotating the butterfly bolt 25 shown in e) above, the braking force at normal time by the brake band 10 shown in d) is adjusted in advance to an extent commensurate with the weight of the cargo A. If the motor 5 is stopped, 1) when the motor 5 is stopped, the rotation of the screw shaft 4 in the direction in which the elevating frame 3 is lowered is braked to keep the cargo A constant. 2) Start motor 5 and lift frame 3 together with cargo A
When lowering the cargo A, the lowering speed is suppressed by the same braking force as above. 3) When raising the cargo A, the braking force exerted on the screw shaft 4 driven by the motor 5 and rotating is made zero, and the waste resistance is reduced. Does not occur-it becomes possible. This 3) is because the one-way transmission means 40 does not transmit the rotation of the screw shaft 4 (and the transmission body 41) in the direction of raising the frame 3 to the brake drum 30, but from this point, it is necessary for the motor 5. Output and power consumption are low. In other words, the transporter 1 can handle a relatively large amount of work even with the battery 6 having a small capacity.

Further, this brake 8 can apply a sudden braking to the screw shaft 4 by manually operating the lever 27 of e) by a worker. Therefore, the braking force preset by the butterfly bolt 25 is smaller than the weight of the cargo A (in this case, there is an advantage that the required output of the motor 5 for lowering the cargo A is small), and the cargo is left as it is. Even if A cannot be held at a constant height, it can be supplemented by a simple manual operation.

With respect to the brake 8, the above-mentioned operating means 20 can be configured according to the invention as shown in FIG. 5 or FIG. 6, for example. In the operation means 120 shown in FIG. 5, the wing nut 123 is turned to set the deflection (extension amount) of the spring 124 to adjust the braking force of the brake band 10 during normal operation in advance. , The bracket between the brackets 122/125 and the frame 126 can be eliminated, and sudden braking can be applied. On the other hand, according to the operating means 220 shown in FIG. 6, the braking force in the normal state can be adjusted by turning the nut member 223 and setting the deflection (compression amount) of the spring 224, and by pulling the handle (lever) 227, the braking force can be rapidly adjusted. You can brake.

If sudden braking by lever operation is not required, the brake band may be fastened on the brake drum by a simpler means such as the operating means 20 'in the conventional brake (see FIG. 7). Even if the sudden braking is not applied thereby, the action of the above 1), 2), and 3) is always applied by applying an appropriate braking force (that is, claim 1).
Is also brought about.

Furthermore, the brake according to claim 1 can be realized by means other than the belt brake. For example, a disc brake type may be used in which the brake drum is replaced with a disc rotor and a caliper sandwiching pad is used in place of the brake band. The built-in one-way transmission means is not limited to the ratchet, and various one-way clutches such as a slug clutch can be used.

Needless to say, the brake of the invention can be widely applied to various lifting devices for lifting and lowering a cargo based on the rotational force of the shaft, other than the transporter of the type shown in the embodiment.

EFFECTS OF THE INVENTION The cargo lifting / lowering device brake of the present invention exerts an appropriate braking force against the falling of a cargo, but does not provide resistance when the cargo is raised. It is easy to operate and at the same time improves power efficiency. Therefore, even with a lifting device equipped with a small (small capacity) and lightweight drive source and energy source,
A sufficient amount of work can be done.

Further, since the brake according to claim 2 can easily stop the cargo by applying sudden braking if necessary, the braking force at the normal time, which should be adjusted and set in advance, may be set to be slightly smaller than the weight of the cargo. This means that the proper setting range of the braking force is wide and adjustment work is easy, and the lifting device can lower the cargo with an extremely small output.

[Brief description of drawings]

1 to 4 are drawings relating to an embodiment of the present invention. FIG. 1 is a sectional front view of a brake for a cargo lifting device (detailed view of I part in FIG. 4), FIG. 2 is a plan view thereof (II-II arrow view of FIG. 1), and FIG. A cross-sectional view in plan view (cross-sectional view taken along the line III-III in FIG. 1), and FIGS. 4 (a) and 4 (b) are a front view and a side-view cross-sectional view of a cargo carrier having its brake as a cargo lifting device. is there. 5 and 6 are sectional views showing another embodiment of the second aspect of the present invention. On the other hand, FIG. 7 is a sectional view showing a conventional brake. 1 ... Carrier (cargo lifting device), 3a ... Cargo support member,
4 ... screw shaft, 5 ... motor (driving source), 8 ... brake, 10 ... brake band (friction member), 20/120/220
...... Operating means, 24 ・ 124 ・ 224 …… Spring, 27 ・ 127
・ 227 …… Lever, 30 …… Brake drum (braked member), 40 …… One-way transmission means, A …… Cargo.

Claims (2)

[Claims] 1. A brake of a type which is provided in a cargo lifting device for lifting and lowering a cargo support member based on a rotational force of a shaft connected to a driving source, and which brakes the rotation of the shaft by a friction member. The surface to be braked by is formed on the surface of a braked member that can rotate separately from the shaft, and between the braked member and the shaft, only the rotation of the shaft when the cargo support member descends is braked. A brake for a cargo lifting device, which is provided with a one-way transmission means for transmitting to a member. 2. A brake drum is used as the member to be braked, a brake band is wound around it as the friction member, and one end of the band is pulled to brake the drum, so that the brake drum is operated to one side from the movable end position. Connect the lever and one end of the band to the above lever, and set a pair of engaging members with a play when the lever is in the movable end position, at a position between the lever and the band so as to pull the elastic force toward the band. The operating means having a spring deflection setting piece capable of adjusting the elastic force of the spring when the interposed spring or lever is at the movable end position is provided by being connected to one end of the band. Brake for cargo lifting device.