JPH04133999A - Positioning device for movable body - Google Patents

Abstract

PURPOSE:To obtain a positioning device capable of being easily automated by providing a first non-circular gear rigidly fixed on a rotational shaft for vertically moving a table, and a detecting shaft rigidly fixing a second non-circular gear meshed with the first non-circular gear thereby transmitting a rotational angle to the detecting shaft in proportion to the displacement amount of the table. CONSTITUTION:As a rotational shaft 14 is rotated, a first arm 12 is rotated, so that a roller located at the end of the first arm 14 is moved on a guide 30 as shown in an arrow (a) and at the same time a roller 36 located at the end of a first arm 32 is moved on a guide 35 of a base 13, thereby vertically moving a table 18 in the direction of an arrow (b). A first non-circular gear 21 is mounted on the rotational shaft 14, and is meshed with a second non-circular gear 22 mounted on the detecting shaft 23. The gears 21 and 22 are respectively designed such that an equivalent rotational angle proportional to the displacement amount with respect to the rotational angle of the shaft 14 changed per unit displacement amount in a range of lifting of the table 18 is transmitted to the detecting shaft 23. A gear 24 is mounted on the detecting shaft 23, and is meshed with a gear 25, so that the rotational angle of the detecting shaft 23 is transmitted to a rotary encoder 26.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention generally relates to a device for positioning the amount of displacement of a movable body in a link-type lifter such as a table lifter.

[Prior Art] As an example of a conventional link type lifter, a link type arm is provided, and a rotation shaft supporting one end of the arm is rotated by moving a rod of a hydraulic cylinder back and forth through a lever fixed to the rotation shaft. There is a table lifter at the other end of the arm that raises and lowers the height of the table.The table height is determined by direct or non-contact detection of the displacement of the table itself or an object placed on the table. This was done by detecting it with a device.

As the detection device, a simple scale plate and pointer placed side by side near the lifter, an electric limit switch and dowel, a proximity switch and sensor, an emitting/receiving photoelectric element, or an ultrasonic element are used.

[Problem to be solved by the invention] By the way, in the above-mentioned table lifter, the rotation angle of the rotation shaft, which is the direct driving means for raising and lowering the height of the table, and the displacement of the table height, which is the movable body, are Since the relationship is a sine function relationship that converts rotational motion into linear motion and is not proportional, the relationship of the sine function is calculated when presetting the height of the tilt table in recent years for automation and labor saving. The disadvantage is that it requires a control system with a built-in microcomputer, making the device complex.

Another problem is that installing the above-mentioned detection device in parallel with the lifter as described above requires space and materials to install the detection device, which may become an obstacle to the work. , there were reliability problems such as malfunctions caused by workers touching them.

Therefore, the present invention provides a positioning device for a link type lifter that is easy to automate and has a shaft that can detect a rotation angle proportional to the amount of displacement of a movable body. The purpose is to eliminate this problem and improve workability and reliability.

[Means for Solving the Problems] The present invention includes at least one arm, a rotation shaft fixed to one end of the arm and rotatably supported, and a movable body provided at the other end of the arm. and a drive means for rotating the rotation shaft to move the movable body at the other end of the arm up and down, the link-type lifter movable body positioning device comprising: a first non-circular gear fixed to the rotation shaft; , a second non-circular gear meshing with the first non-circular gear, a detection shaft to which the second non-circular gear is fixed, and means for detecting the rotation angle of the detection shaft, A movable body positioning device for a link type lifter, characterized in that a rotation angle proportional to the amount of displacement of the movable body is transmitted to the detection shaft by a pair of first and second non-circular gears. do.

[Function] According to the present invention, when the movable body provided at the other end of the arm is moved up and down in a linear motion, the first non-circular gear fixed to the rotation shaft and the rotation angle detection means are provided. A second non-circular gear fixed to the detection shaft engages with the second non-circular gear, and by the rotation of these pair of double-valve circular gears, a rotation angle proportional to the amount of displacement of the movable body is transmitted to the detection shaft, and the positioning of the movable body is accomplished. be done.

[Example] Next, an example of the movable body positioning device for a link type lifter according to the present invention will be described in detail based on FIGS. 1 to 3.

FIG. 1 is a schematic diagram of a hydraulic table lifter, in which one end of a first arm 12 is fixed to a rotating shaft 14 rotatably supported on a pedestal 13, and a roller 31 is provided at the other end.
0 and the table 18 is reused, and 32 is the second
The arm is rotatably supported at one end by a shaft 33 provided at a position symmetrical to the rotation axis 14 of the pedestal 13 of the table 18, and is rotatably supported in the center by an axis intersecting with the first arm 12. The other end is a roller 36 that rolls on the kite 35 of the pedestal 13. Therefore, when the rotation shaft 14 is rotated, the first arm 12 rotates and the first arm 12 rotates. The roller 31 at the other end of the first arm 12 moves over the kite 30 as shown by arrow a in the figure, and at the same time the roller 36 at the other end of the second arm 32 moves over the kite 35 on the pedestal 13. is adapted to move up and down in the direction of the arrow in the figure with respect to the pedestal 13. 15 is a hydraulic cylinder 17 whose one end is fixed to the rotating shaft 14 and the other end is disposed on the pedestal 13. This is a lever that is rotatably connected to the tip of the lever to rotate the rotation shaft 14.

As shown in FIGS. 2 and 3, the rotation shaft 14 has a
A first non-circular gear 21 is attached and meshes with a second non-circular gear 22 attached to a detection shaft 23 as shown in FIG. This pair of first and second non-circular gears 21
．． 22 is configured such that an equal rotation angle θ2 proportional to the amount of displacement by 1 is transmitted to the detection shaft 23 with respect to the rotation angle θ1 of the rotation shaft 14, which changes for each unit displacement amount within the lifting range of the table 18. It is designed based on the lifting range and arm length.

A gear 24 is attached to the detection shaft 23 and meshes with a gear 25 attached to the input shaft of a rotary encoder 26, so that the rotation angle θ2 of the detection shaft 23 is transmitted to the rotary encoder 26.

With the above configuration, the rotation angle θ1 of the rotation shaft 14, that is, the rotation angle θ2 proportional to the amount of vertical displacement of the table 18, can be converted into the number of output pulses of the rotary encoder 26. Positioning is performed by displaying the position according to the number of pulses and by preset control.

The gear ratios of the gears 24 and 25 are selected so as to facilitate processing of the relationship between the unit displacement of the table 18 and the detected pulse, and are designed, for example, to output 1 pulse for every 1 mm of displacement of the table 18.

Note that the output of the rotation angle of the detection axis is not limited to the rotary encoder, and many other means can be used.

[Effects of the Invention] As explained above, the positioning device according to the present invention has a link type lifter having a shaft that can detect a rotation angle proportional to the amount of displacement of a movable body. It enables labor saving and automation by being used in the machine's paper wrapping device, loading device, plate movement automatic changing device, etc., and a detection device is placed near the lifter to detect the displacement of the movable body directly or non-contact. This also has the effect of eliminating the need for detection and improving workability and reliability.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a table lifter, Fig. 2 is a partially enlarged cross-sectional view taken along the line I-I in Fig. 1 and shows an embodiment of the positioning device according to the present invention, and Fig. 3 is a cross-section taken along the line I-I in Fig. 2. It is a figure showing the meshing state of non-circular gears. 12... Arm, 13... Frame, 14... Rotating shaft, 15... Lever 16... Hydraulic cylinder, 17...
...Piston rod, 18...Table, 21...
1st non-circular gear, 22... 2nd non-circular gear, 23... detection shaft, 24. 25... gear train, 26...
・Rotary encoder.

Claims (1)

[Scope of Claims] At least one arm, a rotation shaft fixed to one end of the arm and rotatably supported, a movable body provided at the other end of the arm, and a rotation shaft fixed to one end of the arm and rotatably supported. A movable body positioning device for a link-type lifter comprising a driving means for rotating the movable body at the other end of the arm up and down, comprising: a first non-circular gear fixed to the rotation shaft; A second non-circular gear that meshes with the circular gear, a detection shaft to which the second non-circular gear is fixed, and a means for detecting a rotation angle of the detection shaft, and the first and second pair A movable body positioning device for a link type lifter, characterized in that a rotation angle proportional to the amount of displacement of the movable body is transmitted to the detection shaft by the non-circular gear.