JPH052853U - Fall prevention device for lifting device - Google Patents

Abstract

(57) [Summary] [Object] To provide a fall prevention device for a lifting device, which can reduce the cost of the device and is also highly reliable. [Structure] A swing lever is swingably supported around a timing belt of a lifting device, an idle roller is swingably supported on the swing lever, and a stopper arm is integrally fixed to the swing lever. The roller is constantly brought into pressure contact with the timing belt by the elastic force of the spring stretched between the swing lever and the stationary member, and further, the rotation braking plate that engages with the stopper arm is integrally fixed to the ball screw. When the timing belt is cut, the idle roller becomes free and the rocking lever rocks due to the elastic force of the spring.Therefore, in conjunction with this, the stopper arm moves and engages with the rotary braking plate. , A member that brakes the rotation of the ball screw and raises and lowers it through the rotation braking plate is prevented from falling.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an elevating device that elevates and lowers a table in which a machining head is arranged in a machine tool, for example.

[0002]

[Prior Art]

 For example, as an elevating device for elevating a table on which a machining head is arranged in a machine tool, as shown in FIG. 5, a ball screw 3 is rotatably supported by a frame 1 via bearings 2 and 2, and the ball screw 3 is rotatably supported. 3, a table 4 slidably guided and supported by a guide rail (not shown) axially supported by the frame 1 in parallel with this is screwed through a ball nut 5, and an output shaft 6a of a lifting motor 6 is provided. Is connected to the ball screw 3 via a driving side timing pulley 7, a timing belt 8 and a driven side timing pulley 9. Then, the ball motor 3 is rotated by the lifting motor 6 via the driving side timing pulley 7, the timing belt 8 and the driven side timing pulley 9 to move the table 4 up and down, and the processing head (not shown) arranged on the table 4 is shown. Processing).

By the way, in the above-described lifting device, since the ball screw 3 is always given a rotating force by the weight of the table 4, the driven side timing pulley 7 fixed to the output shaft 6a of the lifting motor 6 and the ball screw 3 are provided. When the timing belt 8 mounted endlessly between the driven side timing pulley 9 and the driven side timing pulley 9 is cut, the ball screw 3 is rotated by the weight of the table 4 to drop the table 4, and the machining head is cured. There was a risk of colliding with tools and work and damaging each other.

Therefore, conventionally, as shown in FIG. 5, a belt disconnection detector 10 for electrically detecting the disconnection of the timing belt 9 is provided near the timing belt 9, and the ball screw 3 is provided with the belt disconnection detector. An electromagnetic brake 11 that operates by an electric signal from the detector 10 is provided, and when the timing belt 8 is cut, the electromagnetic brake 11 is operated by the electric signal from the belt break detector 10 to brake the rotation of the ball screw 3. Therefore, the table 4 is prevented from falling to avoid the collision between the processing head and the jig or the work.

[0005]

[Problems to be solved by the device]

 By the way, in the above-mentioned conventional fall prevention device, when the timing belt 8 is disconnected, the belt disconnection detector 10 that electrically detects the disconnection of the timing belt 8 and the electromagnetic brake 11 that brakes the rotation of the ball screw 3 are combined. Although the table 4 is prevented from falling, the belt cutting detector 10 and the electromagnetic brake 11 are relatively expensive, so that the apparatus cost is high and there may be a malfunction due to disconnection of electric wiring. There is also the problem of lack of reliability.

The present invention has been made in view of the above problems of the related art, and an object of the present invention is to reduce the apparatus cost and improve the reliability.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is configured such that a member for raising and lowering is screwed to a ball screw through a ball nut, and a driven side timing pulley fixed to the ball screw and a drive shaft that is rotationally driven by a lifting motor. A timing belt is installed endlessly between the drive side timing pulley and the drive side timing pulley, and an elevating device is formed.A swing lever is pivotally supported around the timing belt of the elevating device. The idle roller is rotatably supported by the swing lever, the stopper arm is integrally fixed, and the idle roller is fixed to the timing belt by the elastic force of the spring stretched between the swing lever and the stationary member. Fall prevention device for lifting device, which is fixed to the ball screw at all times, and the rotation damping plate that engages with the stopper arm is integrally fixed to the ball screw. To provide a location.

[0008]

[Action]

 According to the fall prevention device for the lifting device of the present invention, when the timing belt is cut, the idle roller becomes free and the swing lever swings due to the elastic force of the spring. The arm moves and engages with the rotary braking plate, which prevents the component that brakes the rotation of the ball screw and raises and lowers through the rotary braking plate from falling.

[0009]

【Example】

 The lifting device fall prevention device of the present invention will be described below with reference to an embodiment shown in FIGS. In this embodiment, the same parts as those in FIG. 5 are designated by the same reference numerals, and the duplicated description will be omitted.

FIG. 1 is a perspective view of an elevating device using a fall prevention device of the present invention, and FIGS. 2 and 3 show the belt uncut state and the belt cut state, respectively.

In FIG. 1 to FIG. 3, reference numeral 12 denotes a swing lever swingably supported by a support shaft 13, which rotatably supports an idle roller 14 at a free end portion thereof and is coaxial with the idle roller 14. Specifically, the stopper arm 15 is integrally fixed, and the idle roller 14 is constantly pressed against the timing belt 8 by the elastic force of the tension spring 16 stretched between the stopper arm 15 and a stationary member (not shown). On the other hand, the stopper arm 15 is provided with a tip portion on the side of the driven side timing pulley 9, and a hook portion 15a bent in an L shape is formed at the tip portion. Reference numeral 17 is a rotary braking plate integrally fixed to the upper end of the ball screw 3, and has locking pieces 17a, 17a for engaging with the hook 15a of the stopper arm 15 at both ends.

Since the present embodiment has the above-mentioned configuration, when the timing belt 8 is cut, the idle roller 14 becomes in a free state, so that the swing lever 12 causes the elastic force of the tension spring 16 as shown in FIG. Oscillates counterclockwise in the figure around the support shaft 13 as a fulcrum, and in conjunction with this, the stopper arm 15 moves to the driven side timing pulley 9 side, and the hook portion 15a of the stopper arm 15 rotates to the rotary braking plate. It engages with one locking piece 17a of 17. As a result, the rotation of the ball screw 3 is braked via the rotation braking plate 17, so that the table 4 is prevented from falling and the collision between the machining head and the jig or work can be prevented.

As described above, according to the present invention, the rotation of the ball screw 3 is stopped by locking the rotary braking plate 17 integrally fixed to the ball screw 3 with the stopper arm 15 that moves in association with the cutting of the timing belt 8. Since the table 4 can be braked to prevent the table 4 from falling, it is not necessary to use an expensive belt break detector or electromagnetic brake as in the conventional case.

It is needless to say that the present invention can be modified not only in the above-described embodiments but also within the scope of the gist of the present invention. For example, in the above-described embodiment, the gate-shaped rotary braking plate 17 in which the locking pieces 17a, 17a are formed at both ends of the strip-shaped long plate is used, but, for example, as shown in FIG. Further, a ratchet-shaped rotary braking plate 18 having a large number of locking pieces 18a engaging with the hook portions 15a of the stopper arm 15 and other rotary braking plates may be used.

[0015]

[Effect of the device]

 According to the present invention, the stopper arm that moves in conjunction with the cutting of the timing belt locks the rotary braking plate integrally fixed to the ball screw, and reliably prevents the lifting member from falling. In addition, it is possible to provide a drop prevention device for a lifting device that is highly reliable as well as reducing the device cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing a fall prevention device for a lifting device according to the present invention.

FIG. 2 is a view showing a state of the present invention when the belt is not cut.

FIG. 3 is a view showing a state when the belt of the present invention is cut.

FIG. 4 is a view showing a modified example of a rotary braking plate.

FIG. 5 is a perspective view of a lifting device using a conventional fall prevention device.

[Explanation of symbols]

 3 Ball screw 4 Table 7 Timing pulley on drive side 8 Timing belt 9 Timing pulley on driven side 12 Swing lever 14 Idle roller 15 Stopper arm 15a Hook part 16 Tension spring 17 Rotation braking plate 17a Locking piece

Claims (1)

[Claims for utility model registration] [Claim 1] A member for raising and lowering is screwed to a ball screw through a ball nut, and is driven to rotate by a driven side timing pulley fixed to the ball screw and a lifting motor. A timing belt is installed endlessly between the drive side timing pulley fixedly mounted on the shaft to form an elevating device, and a swing lever is pivotably supported around the timing belt of the elevating device. An idle roller is rotatably supported by the swing lever, a stopper arm is integrally fixed to the swing lever, and the idle roller is fixed to a timing belt by the elastic force of a spring stretched between the swing lever and a stationary member. It is characterized in that a rotary braking plate that is in constant pressure contact and that engages with the stopper arm is integrally fixed to the ball screw. Lifting device for fall protection equipment.