Unclamping cylinder for numerical control machine tool

Abstract

The unclamping cylinder is provided with a cylinder body, an upper end cover is installed at the upper end of the cylinder body in a sealing fit mode, a movable sleeve with the lower end extending into an inner hole of the cylinder body is arranged in an inner hole of the upper end cover in a sliding mode, and a hydraulic piston which synchronously pushes the movable sleeve to move downwards after being pressed to move downwards is arranged in an inner hole in the upper end of the movable sleeve in a sliding mode. A cutter jacking block is arranged in an inner hole formed in the lower end of the hydraulic piston and is in rolling fit with the inner hole of the hydraulic piston through a bearing; a spacer bush is installed in the cylinder body below the tool jacking block in a rolling mode, a tool changing rod is arranged in the spacer bush in a sliding mode, when the hydraulic piston drives the tool jacking block to move downwards, the tool jacking block abuts against the upper end face of the tool changing rod to push the tool changing rod to move downwards to change tools, and the tool changing rod moves upwards to reset after tool changing is completed. According to the utility model, the bearing is arranged, so that the cutter ejecting block is in rolling fit with the bearing, and when the cutter ejecting block rotates along with the cutter changing rod, the dry friction between the cutter changing rod and the cutter ejecting block in the resetting process can be effectively avoided, and the normal use of the unclamping cylinder is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of numerical control machining, in particular to a knife-beating cylinder used for numerical control machine tools. Background Art

[0002] The tool changing cylinder of machining center is an important component of CNC machine tools, and its main function is to automatically change tools.

[0003] In the existing tool-beating cylinder structure, pneumatic booster is used to push the hydraulic piston to move and simultaneously push the top tool block to move. When the top tool block presses the tool-changing rod, the pulling claw at the front end of the tool-changing rod is stretched open and the tool handle falls off; when the top tool block retracts, the tool-changing rod is reset under the action of the spring, the pulling claw is tightened and pulls the tool handle, completing the spindle tool change.

[0004] Since the replaced tool is in a high-speed rotating state with the spindle, the tool changing rod will also rotate synchronously with the tool in an instant. The tool changing rod reset under the action of the spring retracts at a faster speed, and the top cutter block is fixed on the hydraulic piston, so that the rear end face of the tool changing rod will come into contact with the front end face of the top cutter block, causing a dry friction condition between the tool changing rod and the top cutter block. This condition will continue until the top cutter block is completely reset and loses contact with the tool changing rod. Over time, it will cause serious wear of the parts of the tool cylinder, affecting the normal use of the tool cylinder. Utility Model Content

[0005] The technical problem to be solved by the utility model is: in order to overcome the deficiencies in the prior art, the utility model provides a tool-beating cylinder for a CNC machine tool which can effectively prevent dry friction between parts.

[0006] The technical solution adopted by the utility model to solve its technical problems is: a tool-breaking cylinder used for a CNC machine tool, comprising a cylinder body, an upper end cover is installed in a sealing manner at the upper end of the cylinder body, a movable sleeve with a lower end extending into the inner hole of the cylinder body is slidably provided in the inner hole of the upper end of the upper end cover, a hydraulic piston is slidably provided in the inner hole of the upper end of the movable sleeve, and the movable sleeve is pushed downward synchronously after being pressed downward, a top cutter block is provided in the inner hole of the lower end of the hydraulic piston, and the top cutter block and the inner hole of the hydraulic piston are rollingly matched through bearings; a spacer sleeve is slidably installed in the cylinder body below the top cutter block, and a tool-changing rod is slidably provided in the spacer sleeve, when the hydraulic piston drives the top cutter block to move downward, the top cutter block presses on the upper end surface of the tool-changing rod and pushes the tool-changing rod to move downward for tool changing, and the tool-changing rod moves up and resets after completing the tool changing.

[0007] Specifically, the hydraulic piston includes a piston part and an annular part of an integrated structure. The diameter of the piston part is larger than that of the annular part. The outer periphery of the piston part slides with the inner hole of the upper end of the movable sleeve, the outer ring of the bearing fits with the inner hole of the annular part, and the top cutter block fits with the inner ring of the bearing.

[0008] Furthermore, the upper end of the inner wall of the movable sleeve has an inner step, and the middle portion of the outer wall of the movable sleeve has an outer step. When the hydraulic piston moves downward, the bottom surface of the piston portion presses against the upper end surface of the inner step. A first spring is provided between the lower end surface of the outer step and the cylinder body to push the movable sleeve upward and reset after the tool changing rod completes the tool change.

[0009] Furthermore, a pressing sleeve is slidably provided inside the upper end of the spacer sleeve, and the pressing sleeve has a stepped inner hole. The tool changing rod is gap-matched with the small hole at the bottom of the stepped inner hole, and a retaining ring is embedded on the outer periphery of the tool changing rod and pressed on the stepped surface of the stepped inner hole.

[0010] Furthermore, a second spring is provided between the bottom surface of the pressing sleeve and the middle portion of the spacer sleeve to push the tool changing rod to move upward and reset after the tool changing rod completes the tool changing.

[0011] Furthermore, a pressure cover is fixed on the upper end surface of the spacer.

[0012] The beneficial effect of the utility model is that the utility model arranges a bearing between the top cutter block and the inner hole of the hydraulic piston, so that the top cutter block and the bearing form a rolling fit. When the top cutter block rotates with the tool changing rod, the dry friction between the top cutter block and the tool changing rod during the resetting process can be effectively avoided, thereby ensuring the normal use of the tool cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described below with reference to the accompanying drawings and implementation examples.

[0014] Figure 1 It is a structural diagram of the present utility model.

[0015] In the figure: 1. cylinder body, 2. upper end cover, 3. movable sleeve, 3-1. inner step, 3-2. outer step, 4. hydraulic piston, 4-1. piston part, 4-2. annular part, 5. top cutter block, 6. bearing, 7. spacer, 8. tool changing rod, 9. first spring, 10. pressing sleeve, 11. retaining ring, 12. second spring, 13. pressure cover. DETAILED DESCRIPTION

[0016] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0017] like Figure 1The tool-beating cylinder used in a CNC machine tool shown in the figure has a cylinder body 1, an upper end cover 2 is installed on the upper end of the cylinder body 1, a movable sleeve 3 is slidably provided in the inner hole of the upper end cover 2, and the lower end portion of the movable sleeve 3 extends into the inner hole of the cylinder body 1, the upper end of the inner wall of the movable sleeve 3 has an inner step 3-1, and the middle part of the outer wall of the movable sleeve 3 has an outer step 3-2, the outer wall of the movable sleeve 3 where the inner step 3-1 is located is sealed with the inner hole of the upper end cover 2, the upper end surface of the outer step 3-2 is close to the bottom surface of the upper end cover 2, and the outer peripheral surface of the outer step 3-2 is sealed with the inner hole of the cylinder body 1 and can slide along the inner hole of the cylinder body 1.

[0018] A hydraulic piston 4 is provided in the inner hole of the movable sleeve 3 above the inner step 3-1, which is pressed downward by an external force. The hydraulic piston 4 includes a piston part 4-1 and an annular part 4-2 of an integral structure. The diameter of the piston part 4-1 is larger than the diameter of the annular part 4-2. The outer periphery of the piston part 4-1 slides with the inner hole of the upper end of the movable sleeve 3, and a top cutter block 5 is provided in the inner hole of the annular part 4-2; the top cutter block 5 has a cylindrical part and a disc of an integral structure, and a bearing 6 is installed between the outer periphery of the cylindrical part of the top cutter block 5 and the inner hole of the annular part 4-2. The outer ring of the bearing 6 cooperates with the inner hole of the annular part 4-2, and the outer periphery of the cylindrical part of the top cutter block 5 cooperates with the inner ring of the bearing 6, so that the top cutter block 5 can form a rolling fit with the hydraulic piston 4 through the bearing 6.

[0019] A spacer sleeve 7 is rotatably installed in the cylinder body 1 below the top knife block 5, a pressure cover 13 is fixed to the upper end face of the spacer sleeve 7, a tool changing rod 8 is slidably provided in the spacer sleeve 7, and a pressing sleeve 10 is slidably provided in the upper end of the spacer sleeve 7; the pressing sleeve 10 has a stepped inner hole, the tool changing rod 8 is gap-matched with the small hole at the lower part of the stepped inner hole, and a retaining ring 11 is embedded on the outer periphery of the tool changing rod 8 and pressed on the step surface of the stepped inner hole.

[0020] When the hydraulic piston 4 drives the top cutter block 5 to move downward, the top cutter block 5 presses on the upper end surface of the tool changing rod 8 and pushes the tool changing rod 8 to move downward to change the tool. After the tool changing is completed, the tool changing rod 8 moves upward and resets.

[0021] When the hydraulic piston 4 is pressed down, the bottom surface of its piston part 4-1 presses against the upper end surface of the inner step 3-1 of the movable sleeve 3 and simultaneously pushes the movable sleeve 3 downward. A first spring 9 is provided between the lower end surface of the outer step 3-2 and the cylinder body 1 to push the movable sleeve 3 to move upward and reset after the tool changing rod 8 completes the tool change.

[0022] A second spring 12 is provided between the bottom surface of the pressing sleeve 10 and the middle of the spacer sleeve 7 to push the tool-changing rod 8 to move upward and reset after the tool-changing rod 8 completes the tool change.

[0023] When the tool changing rod 8 moves up and resets after completing the tool changing, the tool is driven by the main shaft to rotate rapidly, driving the tool changing rod 8 to rotate synchronously. When the rotating tool changing rod 8 moves up and contacts the end face of the top knife block 5, the top knife block 5 and the bearing 6 form a rolling fit, so that the top knife block 5 rotates with the tool changing rod 8 and continues until the top knife block 5 is completely reset and disengaged from the tool changing rod 8, thereby avoiding the dry friction between the tool changing rod 8 and the top knife block 5 during the reset process, and ensuring the normal use of the knife cylinder.

[0024] Based on the above-mentioned ideal embodiment of the present invention, and in accordance with the above description, relevant personnel can make various changes and modifications without departing from the technical scope of the present invention. The technical scope of the present invention is not limited to the content of the specification, but must be determined according to the scope of the claims.

Claims

1. A cutting cylinder for a numerically controlled machine tool, comprising a cylinder body (1), characterized in that: The upper end of the cylinder body (1) is sealed and fitted with an upper end cover (2), and a movable sleeve (3) is slidably provided in the inner hole of the upper end cover (2) and its lower end extends into the inner hole of the cylinder body (1). A hydraulic piston (4) is slidably provided in the inner hole of the upper end of the movable sleeve (3) and is pressed and moved downward to synchronously push the movable sleeve (3) downward. A top knife block (5) is provided in the inner hole of the lower end of the hydraulic piston (4). The top knife block (5) and the inner hole of the hydraulic piston (4) are rolling fitted through a bearing (6); a spacer sleeve (7) is slidably provided in the cylinder body (1) below the top knife block (5), and a tool changing rod (8) is slidably provided in the spacer sleeve (7). When the hydraulic piston (4) drives the top knife block (5) to move downward, the top knife block (5) presses on the upper end surface of the tool changing rod (8) and pushes the tool changing rod (8) downward to change the tool. After the tool changing rod (8) completes the tool changing, it moves upward and resets.

2. The tool-beating cylinder for a CNC machine tool according to claim 1, wherein: The hydraulic piston (4) comprises a piston portion (4-1) and an annular portion (4-2) of an integral structure. The diameter of the piston portion (4-1) is larger than that of the annular portion (4-2). The outer periphery of the piston portion (4-1) is in sliding engagement with the inner hole of the upper end of the movable sleeve (3). The outer ring of the bearing (6) is in engagement with the inner hole of the annular portion (4-2). The top cutter block (5) is in engagement with the inner ring of the bearing (6).

3. The tool-beating cylinder for a CNC machine tool according to claim 2, wherein: The upper end of the inner wall of the movable sleeve (3) has an inner step (3-1), and the middle part of the outer wall of the movable sleeve (3) has an outer step (3-2). When the hydraulic piston (4) moves downward, the bottom surface of the piston part (4-1) presses against the upper end surface of the inner step (3-1). A first spring (9) is provided between the lower end surface of the outer step (3-2) and the cylinder body (1) to push the movable sleeve (3) upward and reset after the tool changing rod (8) completes the tool changing.

4. The tool-beating cylinder for a CNC machine tool according to claim 1, wherein: A pressing sleeve (10) is slidably provided inside the upper end of the spacer sleeve (7), and the pressing sleeve (10) has a stepped inner hole. The tool changing rod (8) is gap-matched with the small hole at the lower part of the stepped inner hole, and a clamping ring (11) is embedded on the outer periphery of the tool changing rod (8) and pressed on the stepped surface of the stepped inner hole.

5. The tool-beating cylinder for a CNC machine tool according to claim 4, wherein: A second spring (12) is provided between the bottom surface of the pressing sleeve (10) and the middle of the spacer sleeve (7) to push the tool changing rod (8) upward and reset after the tool changing rod (8) completes the tool changing.

6. The tool-beating cylinder for a CNC machine tool according to claim 4, wherein: A pressure cover (13) is fixed on the upper end surface of the spacer (7).

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