Zero-reset device and numerical control equipment

Abstract

The present application relates to a kind of zero return device and numerical control equipment, the numerical control equipment has the zero return device, the zero return device includes zero return combination switch, deceleration block and limit block;Deceleration block, limit block and the position of deceleration switch, extreme speed switch of zero return combination switch are matched, while being partially overlapped in vertical direction, along the parallel arrangement of zero return component operating direction, and deceleration block is located in limit block front end in the direction of facing zero return.The present application, machine tool does not need to consider the position of slide table when zeroing, as long as limit alarm does not appear, it can operate zeroing, machine tool automatically identifies deceleration block, then retreats to find zero point and stops, while setting zero point signal.No additional accessories, such as deceleration switch damage, zeroing failure, machine tool can also normally alarm alarm when pressing limit switch.

Description

Technical Field

[0001] This invention belongs to the field of CNC equipment technology, and relates to a zero-return device for CNC equipment, specifically involving the switch for the zero-return point and the position setting of the stop block. Background Technology

[0002] The mechanical zero point of a CNC machine is a fixed point on the machine tool, determined by the zero-point signal (usually called the one-revolution signal) in the encoder of the servo motor installed on the machine tool. Under normal circumstances, machine tools with a relative zero-point structure need to perform a zero-point return operation before operation. The general method is to install a deceleration switch near the maximum travel in the X or Z direction. After the machine tool presses the deceleration switch, it decelerates to a specified low speed and waits for the one-revolution signal to appear. After receiving the one-revolution signal, it stops moving and memorizes the coordinates of that point as the zero point. This is usually called the machine tool returning to the reference point. Currently in the field of machining, relative zero-point structure equipment must be equipped with a mechanical stop block. The stop block is installed on the slide of the machine tool, and the length of the stop block must be greater than or equal to 2.5 times the lead of the transmission screw used.

[0003] For machine tools with relative zero-point setting, there are generally two methods for homing: one is to press the deceleration switch first, the slide decelerates to the homing low speed, and after passing the deceleration block at low speed, the movement stops after detecting the zero-point pulse, the zero point is calibrated, and the mechanical homing operation is completed; the other is to pass the deceleration block, the slide returns at the homing low speed, and after disengaging from the deceleration block, the movement stops after detecting the zero-point pulse, the zero point is calibrated, and the mechanical homing operation is completed.

[0004] Both of the aforementioned relative zeroing schemes have advantages and disadvantages: When the machine tool is used at its maximum stroke, the deceleration stop block will press against the deceleration switch. If this happens too often each day, the switch will reach its usage limit in a short period, prematurely ending its lifespan. If the deceleration switch is intentionally not pressed, it will inevitably shorten the effective length of the machine tool guideway. Furthermore, if the limit switch is not pressed for a long time, it is prone to corrosion and other malfunctions, failing to function without being detected. Moreover, if the machine tool (stop block) happens to stop between the deceleration switch and the limit switch, zeroing at this time will cause the machine tool to experience overtravel. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention proposes a zeroing device that can return to zero as long as the slide table does not have a limit alarm, and the zero point position is greatly reduced by the occupancy of the guide rail. Each time the zeroing is returned to zero, a deceleration is applied and a limit switch is applied. The present invention also proposes a CNC equipment with the zeroing device.

[0006] This invention is achieved through the following technical solution:

[0007] The aforementioned zero-return device includes a zero-return combination switch, a deceleration block, and a limit block; the zero-return combination switch includes stacked deceleration switches and limit switches, which are stacked vertically along the running direction of the return component; the deceleration block and limit block are positioned to match the deceleration switches and limit switches, are arranged parallel to the running direction of the return component, and partially overlap in the vertical direction, with the deceleration block facing the zero-return direction located at the front end of the limit block.

[0008] The zero-return device, wherein the overlapping portion of the deceleration block and the limit block has a size of 4-6mm.

[0009] The zero-return device, wherein: the deceleration block is an isosceles trapezoidal structure with two symmetrical inclined surfaces, and the two inclined surfaces at the front and rear ends of the deceleration block match the contact fingers of the deceleration switch, and when moving, pressing the deceleration switch triggers a deceleration signal.

[0010] The zero-return device, wherein: the limit block is an isosceles trapezoidal structure with two symmetrical inclined surfaces, the two inclined surfaces at the front and rear ends of the limit block match the contact fingers of the limit switch, and are at the same height as the deceleration block.

[0011] The aforementioned CNC equipment includes a bed and a slide table, wherein a slide rail is provided on the operating platform of the bed; the slide table is slidably mounted on the slide rail; and the equipment has a zero-return device as described above.

[0012] The CNC equipment, wherein: the zero-return combination switch is mounted on the guide rail of the bed via a bracket; the deceleration switch and the limit combination switch are stacked one on top of the bracket, with the switch contacts extending towards the slide table; the deceleration stop block is mounted on the side of the slide table, matching the height of the deceleration switch; the limit stop block is mounted on the side of the slide table, located diagonally below the deceleration stop block, partially overlapping the deceleration stop block in the vertical direction, and matching the height of the limit switch.

[0013] The CNC equipment, wherein: the control system includes a PLC, and the PLC determines and identifies the zero point according to the working mode when the deceleration switch and the limit switch are pressed simultaneously in the zero-return mode. Beneficial effects

[0014] The zero-return device of this invention, through the partial overlap of the deceleration block and the limit block, simultaneously presses the limit switch at the end of the deceleration motion, shortening the zero-return stroke of the returning component. Furthermore, it eliminates the need to consider the specific position of the returning component; as long as the limit switches at both ends are not in a limit alarm state, it can return to zero, finding the zero point according to a pre-set method. The zero-point position also significantly reduces guide rail occupancy. Similarly, if the deceleration switch malfunctions and fails to send a normal signal, the machine tool can also identify and alarm. In particular, this solution requires no additional accessories, has a simple structure, low cost, is convenient to install and maintain, and is stable and reliable in use, making it widely applicable to automated equipment. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the zero-return device of the present invention;

[0016] Figure 2 This is a schematic diagram of the zero-return process of the zero-return device of the present invention;

[0017] Figure 3 This is a schematic diagram of the structure of a CNC device with a zero-return device according to an embodiment of the present invention;

[0018] Figure 4 for Figure 3 A magnified view of part A. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0020] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a connection that allows communication between components; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. The following will describe some embodiments of this application in detail with reference to the accompanying drawings.

[0021] The embodiments of this application will be further described below with reference to the accompanying drawings.

[0022] like Figure 1 As shown, the zero-return device 3 of the present invention includes a zero-return combination switch 31, a deceleration block 32, and a limit block 33;

[0023] The zero-return combination switch 31 includes a stacked deceleration switch 312 and a limit switch 313, which are stacked vertically along the running direction of the return components.

[0024] The positions of the deceleration block 32, the limit block 33, the deceleration switch 312, and the limit switch 313 are matched. They are arranged parallel to the running direction of the components and partially overlap in the vertical direction. That is, after the deceleration switch presses on the deceleration block 32, before it leaves, the limit switch 313 presses on the limit block 33. The optimal size S of the overlapping part is 4-6mm.

[0025] The zero-return process of this device will be explained using the zero point setting of a servo motor as an example. Figure 2 As shown: First, the slide table runs, the deceleration switch of the combination switch presses against the deceleration block, triggering the deceleration signal, and the slide table decelerates. Second, the limit switch of the combination switch presses against the limit block, triggering the limit signal, and the slide table stops running. Third, after pausing, the slide table reverses at the zero-return speed, and the limit switches of the combination switch move away from the limit blocks in sequence, and the deceleration switches move away from the deceleration blocks in the reverse rotation. Fourth, the slide table stops when the zero-point signal appears, and the zero-return is completed.

[0026] This zero-return device, by overlapping the deceleration block 32 and the limit block 33 in the vertical part of the return component's running direction, presses the limit switch at the end of the deceleration movement, shortening the zero-return stroke of the return component. Moreover, it does not need to consider the specific position of the return component. As long as the limit switches at both ends are not pressed and are in the limit alarm state, it can return to zero and find the zero point according to the preset method. Similarly, if the deceleration switch malfunctions and cannot send a normal signal, the machine tool can also identify and alarm.

[0027] When the overlap is 4-6mm, the slide can return to zero in time with a short stroke, and the zero point position greatly reduces the occupancy of the guide rail, which can reduce the length of the slide rail and reduce costs.

[0028] The CNC equipment of this invention is equipped with the zero-return device of this invention, and the following description uses a horizontal CNC lathe as an example. Figure 3 , Figure 4 As shown, the device includes a bed 1, a slide 2, a homing device 3, and a control system (not shown).

[0029] The operating platform of the bed 1 is equipped with slide rails 11.

[0030] The slide table 2 is slidably mounted on the slide rail 11 of the bed 1 and is driven by the servo motor 21 to reciprocate along the slide rail 21 on the operating platform.

[0031] The zero-return device 3 is used for the slide table 2 to return to zero, and includes a zero-return combination switch 31, a limit stop 32, and a deceleration stop 33. The zero-return combination switch 31 is mounted on the bed 1 via a bracket 311, and is combined with a deceleration switch 312 and a limit switch 313. The bracket 311 is fixedly mounted on the guide rail 11 of the bed 1. The deceleration switch 312 and the limit switch are stacked on the bracket 311, and the switch contacts extend toward the slide table 2.

[0032] The deceleration block 32 is installed on the side of the slide table 2 and is matched with the height of the deceleration switch 312. The deceleration block 32 is an isosceles trapezoidal structure with two symmetrical inclined surfaces. The two inclined surfaces at the front and rear ends of the deceleration block 32 are matched with the contact fingers that contact the deceleration switch 32. When moving, the deceleration switch is pressed to trigger the deceleration signal.

[0033] The limit block 33 is installed on the side of the slide table 2, located diagonally below the deceleration block 32, and partially overlaps with the deceleration block 32 in the vertical direction, matching the height of the limit switch 313. The limit block 33 is an isosceles trapezoidal structure with two symmetrical inclined surfaces. The two inclined surfaces at the front and rear ends of the limit block 33 are matched with the contact fingers that contact the limit switch 313, and are at the same height as the deceleration block 32. When moving, it presses against the limit switch, triggering the limit signal. The dimension of the vertical overlap between the limit block 33 and the deceleration block 32 is preferably 4-6 mm.

[0034] The front end of the deceleration block 32 facing the zero-return direction is the deceleration switch 312, and the rear end is the limit block 33. The position of the limit block 32 coincides with the front end of the limit block 33 by about 5 mm. The purpose of the coincidence is so that when the machine tool is running back to zero, the deceleration switch is pressed and the limit switch is pressed at the end of the deceleration movement, so that the deceleration signal is sent and then the limit signal is sent.

[0035] The control system includes a PLC, and the zero-point identification relies on the PLC to determine the operating mode. Using the PLC to determine the zero-point identification based on the operating mode, only in homing mode, when two switches are pressed simultaneously, does not necessarily mean that the slide limit has been exceeded.

[0036] By overlapping the deceleration block 32 and the limit block 33 by at least 5 cm, the deceleration switch 312 and the limit switch 313 are pressed simultaneously when returning to zero. After the PLC recognizes this, it blocks the overtravel limit alarm and sends a slide table 2 exit signal. The slide table 2 returns at a low speed to zero. After disengaging from the deceleration block 32, it stops and sets the zero point by detecting the one-turn signal from the encoder.

[0037] The CNC machine tool slide zero-return device of this invention does not require consideration of the slide's specific position during zero-return. As long as the limit switches at both ends are not pressed and the machine is not in a limit alarm state, it can return to zero and find the zero point according to a preset method. Even if the deceleration switch malfunctions and cannot send a normal signal, causing the machine tool to fail to find the zero point during zero-return, it can still issue a limit alarm and identify the deceleration switch malfunction through a program to trigger an alarm. In particular, this solution does not require additional accessories, has a simple structure, low cost, is convenient to install and maintain, and is stable and reliable in use, making it widely applicable to automated equipment.

[0038] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be embraced within this application.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.

Claims

1. A zeroing device, characterized by: The zero reset device comprises a zero reset combination switch, a deceleration block and a limit block. The zero reset combination switch comprises a deceleration switch and a limit switch stacked in the vertical direction along the running direction of the zero reset component. The deceleration block and the limit block are arranged in parallel along the running direction of the zero reset component and partially overlap in the vertical direction, and the deceleration block is located in front of the limit block in the zero reset direction.

2. The zeroing device of claim 1, wherein: The size of the overlapping part of the deceleration block and the limit block is 4-6mm.

3. The zeroing device of claim 1, wherein: The deceleration block is an isosceles trapezoid structure with two symmetrical inclined surfaces, and the two inclined surfaces at the front and rear ends of the deceleration block are matched with the contact fingers of the deceleration switch, and the contact fingers press the deceleration switch to trigger a deceleration signal when moving.

4. The zeroing device of claim 1, wherein: The limit block is an isosceles trapezoid structure with two symmetrical inclined surfaces, and the two inclined surfaces at the front and rear ends of the limit block are matched with the contact fingers of the limit switch, and the limit block is the same height as the deceleration block.

5. A numerical control apparatus, comprising a bed and a slide, the bed is provided with a slide rail on an operating platform; the slide is slidingly assembled on the slide rail; characterized in that: The equipment has the zero reset device as claimed in any one of claims 1-4.

6. The numerically controlled apparatus according to claim 5, wherein: The zero reset combination switch is mounted on the guide rail of the bed body through a support, and the deceleration switch and the limit combination switch are stacked in the vertical direction on the support, and the switch contact extends towards the slide table direction. The deceleration block is installed on the side of the slide table and matched with the height of the deceleration switch. The limit block is installed on the side of the slide table and located obliquely below the deceleration block, partially overlaps with the deceleration block in the vertical direction, and matched with the height of the limit switch.

7. The numerically controlled apparatus according to claim 5, wherein: The equipment comprises a control system, and the control system comprises a PLC which identifies the zero point according to the working mode when the deceleration switch and the limit switch are pressed simultaneously in the zero reset mode.

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