Valve pipe cutting device for a stop valve

Abstract

The application discloses a valve pipe cutting processing device of a stop valve and relates to the technical field of machining, which comprises a workbench, a bottom die, a necking die, a hydraulic cylinder and a motor, a fixing cavity for fixing the end part of the valve pipe of the stop valve is arranged in the bottom die; a plurality of sliders arranged in an array in a circle are arranged in the necking die, the sliders are arranged on the necking die in a radial sliding mode, and the plurality of sliders are closest in interval and form the necking die by the surrounding of inner walls in a default state; and a transmission block is arranged on the supporting die in an axial sliding mode. The valve pipe cutting processing device of the stop valve controls the lifting of the transmission block through a single driving source of the hydraulic cylinder, and automatically switches the necking and chamfering modes. Not only is the equipment structure simplified and the manufacturing cost reduced, but also the accurate connection between the two machining procedures is ensured, and the machining precision and efficiency are greatly improved. The whole system realizes function conversion in a mechanical linkage mode, and has the advantages of high reliability, simple maintenance and the like.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and more specifically to a valve tube cutting and machining device for a gate valve. Background Technology

[0002] The ends of the copper valve tube located inside the gate valve require diameter reduction and chamfering to meet usage requirements. Copper, as a typical soft metal, while possessing excellent sealing performance and corrosion resistance in gate valve manufacturing, presents unique processing challenges during machining: its soft texture and high plasticity make it highly susceptible to surface damage such as scratches and indentations during clamping and processing; simultaneously, copper exhibits significant elastic recovery characteristics after plastic deformation, making it difficult to control the dimensional stability after diameter reduction. Traditional processing methods require separate diameter reduction and chamfering processes, which exposes a series of prominent problems in the machining of copper valve tubes. First, multiple clamping and positioning not only increase production auxiliary time, but more importantly, due to the softness of copper, repeated clamping easily causes surface damage and deformation of the valve tube, leading to changes in the machining datum and making it difficult to guarantee machining accuracy. Second, the low production efficiency caused by the dispersed processes is particularly evident in the machining of copper valve tubes. The need to transfer workpieces between different machines increases the production cycle and raises the risk of collision damage to the copper workpieces during transport.

[0003] Based on publication number CN113695930A, a valve cutting and processing device is disclosed. An adjusting spindle is configured, and an arc-shaped groove is formed on the inner surface of an adjusting arc-shaped plate. The adjusting arc-shaped plate and the adjusting plate are rotatably connected via a rotating rod. The adjusting spindle, connected to the adjusting arc-shaped plate, effectively adjusts the saw blade milling cutter in the cutting mechanism. A pressure plate pull rod is provided on the lower surface of a fixed pressure plate, and the pressure plate pull rod is fixedly connected to an L-shaped tension rod. A tensioning hydraulic cylinder is provided on the inner surface of the L-shaped tension rod, effectively fixing the valve. A left and right slide table is slidably mounted on the upper surface of a slide rail, driving the cutting mechanism to slide simultaneously to the middle worktable. The saw blade milling cutters, located on both sides of the cutting mechanism, simultaneously process and cut the valve body, effectively improving processing efficiency.

[0004] In existing technologies, the fixing mechanism for valves is typically designed to be quite complex to ensure positioning accuracy during processing. For example, some patented solutions employ a combined clamping mechanism consisting of a fixed pressure plate, a pressure plate pull rod, an L-shaped tensioning rod, and a tensioning hydraulic cylinder. While this structure provides sufficient clamping force and reliability, it also introduces a series of problems: the overall structure is complex, occupies a large space, and the system response time may be prolonged due to the coordination of multiple components. Furthermore, after metal plastic processing (such as necking), the workpiece is prone to springback due to the inherent elastic recovery characteristics of the material, leading to deviations in the final processed dimensions from the expected target and affecting forming accuracy. Summary of the Invention

[0005] The purpose of this invention is to provide a valve tube cutting and machining device for a shut-off valve, which solves the above-mentioned problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a valve tube cutting and processing device for a stop valve, comprising a worktable, a bottom mold, a necking mold, a hydraulic cylinder and a motor, wherein the bottom mold has a fixing cavity for fixing the end of the stop valve tube;

[0007] Multiple sliders are arranged in a circular array within the slit mold. The sliders are slidably disposed on the slit mold along the radial direction. In the default state, the multiple sliders have the shortest spacing and the inner walls enclose each other to form the slit mold.

[0008] A transmission block axially slides on the support mold, having a high position and a low position that are relatively arranged, and the transmission block is provided with a transmission rod for driving the slider during the switching of the high and low position states.

[0009] It also includes a grinding part fixedly installed at the lower end of the support mold. When the transmission block descends to the low position, the grinding part abuts against the valve pipe port after the narrowing.

[0010] The motor used to drive the transmission rotation when the transmission block is in the low position is located on the reducing die.

[0011] Preferably, a wedge is slidably disposed within the fixed cavity, and the fixed cavity has a conical structure that is larger at the top and smaller at the bottom.

[0012] Preferably, a fixing rod is fixedly provided on the constriction mold, and a support mold for supporting the inside of the valve pipe port is fixedly provided at the bottom end of the fixing rod.

[0013] Preferably, the device also includes a hydraulic cylinder mounted on the reducing die, and the transmission block is rotatably connected to the output end of the hydraulic cylinder.

[0014] Preferably, a rotating ring is rotatably provided on the transmission block, and a transmission rod is provided between the rotating ring and the slider for transmission connection.

[0015] Preferably, the device also includes multiple limiting wheels arranged in a circumferential array within the constriction mold, and the limiting wheels are flush with the inner wall end face formed by the slider in the default state.

[0016] Preferably, the reducing die is also provided with a serrated structure corresponding to the grinding part, and the transmission block and the serrated structure are interleaved when the transmission block is in the low position.

[0017] Preferably, the cone angle of the cone-shaped structure of the fixed cavity is 15° to 45°.

[0018] Preferably, the transmission rod is a rigid connecting rod, with one end hinged to the rotating ring and the other end hinged to the slider.

[0019] Preferably, the support mold is detachable and fixed to the bottom of the fixing rod with bolts.

[0020] In the above technical solution, the valve tube cutting processing device for a gate valve provided by the present invention has the following beneficial effects: The lifting and lowering of the transmission block is controlled by a single hydraulic cylinder drive source, automatically switching between necking and chamfering modes. This not only simplifies the equipment structure and reduces manufacturing costs, but more importantly, ensures precise connection between the two processing steps, greatly improving processing accuracy and efficiency. The entire system uses mechanical linkage to achieve function conversion, offering advantages such as high reliability and easy maintenance. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0022] Figure 1 This is a schematic diagram of the overall three-dimensional structure provided in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the overall cross-sectional structure provided in an embodiment of the present invention;

[0024] Figure 3 A side view provided for an embodiment of the present invention;

[0025] Figure 4 A side sectional view provided for an embodiment of the present invention;

[0026] Figure 5 Provided for embodiments of the present invention Figure 3 Enlarged schematic diagram of structure A in the middle;

[0027] Figure 6 This is a schematic diagram of the transmission block structure provided in an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the internal structure of the narrowing mold provided in an embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Workbench; 2. Bottom mold; 21. Fixed cavity; 22. Wedge block; 3. Sliding plate; 4. Narrowing mold; 41. Fixed rod; 42. Support mold; 43. Slider; 44. Transmission block; 441. Rotary ring; 442. Transmission rod; 443. Lower locking block; 444. Upper gear; 445. Grinding part; 45. Limiting wheel; 5. Assembly plate; 51. Hydraulic cylinder; 52. Motor; 521. Drive gear. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0032] like Figure 1-7 As shown, a valve tube cutting and processing device for a stop valve includes a worktable 1, a bottom mold 2, a necking mold 4, a hydraulic cylinder 51, and a motor 52. The bottom mold 2 has a fixing cavity 21 for fixing the end of the stop valve tube.

[0033] Multiple sliders 43 are arranged in a circular array within the reducing mold 4. The sliders 43 slide radially on the reducing mold 4, and the multiple sliders 43 have the shortest spacing and the inner walls enclose each other to form the reducing mold in the default state.

[0034] A transmission block 44 is axially slidably disposed on the support mold 42. It has a high position and a low position disposed opposite to each other, and a transmission rod 442 is provided on the transmission block 44 for driving the slider 43 during the switching of the high and low position states.

[0035] It also includes a grinding part 445 fixedly installed at the lower end of the support mold 42. When the transmission block 44 descends to the low position, the grinding part 445 abuts against the valve pipe port after the narrowing.

[0036] The motor 52, which drives the transmission block 44 to rotate in the low position state, is located on the necking mold 4.

[0037] Specifically, the sliding plate 3 is slidably mounted on the worktable 1 and moves linearly via a guide rail or slide rail mechanism. The necking mold 4 is fixedly mounted on the sliding plate 3. The assembly plate 5 is also fixedly mounted on the necking mold 4, and the motor 52 is mounted on the assembly plate 5. A drive gear 521 is fixedly mounted on the output shaft of the motor 52, and an upper gear 444 is fixedly mounted on the upper end of the transmission block 44. When the transmission block 44 descends to a predetermined position, the upper gear 444 meshes with the drive gear 521, and the slider 43 is radially slidably mounted on the necking mold 4 via a guide groove.

[0038] Furthermore, it also includes a hydraulic cylinder 51 mounted on the necking mold 4, and the transmission block 44 is rotatably connected to the output end of the hydraulic cylinder 51 via a bearing. The operator first inserts the copper valve tube of the shut-off valve vertically (the copper tube end inside the shut-off valve) into the fixed cavity 21 of the bottom mold 2, and fixes it within the fixed cavity 21 (the specific fixing method is detailed below), ensuring that the end of the valve tube protrudes at an appropriate length (usually 1.2-1.5 times the necking length). After clamping, the hydraulic system is started. At this time, the sliding plate 3 is driven downwards by an electric telescopic rod or hydraulic cylinder, and the sliding plate 3 drives the necking mold 4 and the slider 43 to move downwards synchronously. At this time, the transmission block 44 is in a high position, and the slider 43 remains in the default state, that is, the inner wall of the slider 43 forms a necking mold. This necking mold, as the sliding plate 3 moves downwards, squeezes and shapes the valve tube end, completing the necking.

[0039] Subsequently, the transmission block 44 is driven further down by the hydraulic cylinder 51, causing the upper gear 444 to mesh with the drive gear 521. The grinding part 445 contacts the valve pipe port, and then the motor 52 is driven. The drive gear 521 of the motor 52 outputs torque to chamfer the valve pipe port. During the chamfering process, the rotation speed, feed force, and processing time can all be precisely controlled according to the characteristics of the copper material to ensure a smooth chamfered surface.

[0040] After the chamfering process is completed, motor 52 stops operating first. Then, the hydraulic system executes a reset procedure: hydraulic cylinder 51 pulls transmission block 44 to a high position, during which transmission rod 442 drives slider 43 to radially retract and reset; simultaneously, sliding plate 3 drives the necking mold 4 to move upwards as a whole, support mold 42 exits from the valve tube, and limit wheel 45 disengages from the valve tube surface. The entire processing cycle is short, and seamless connection between the necking and chamfering processes is achieved.

[0041] In the aforementioned technology, the lifting and lowering of the transmission block 44 is controlled by a single hydraulic cylinder 51, automatically switching between the necking and chamfering modes. This not only simplifies the equipment structure and reduces manufacturing costs, but more importantly, it ensures precise connection between the two processing steps, greatly improving processing accuracy and efficiency. The entire system uses mechanical linkage to achieve function conversion, offering advantages such as high reliability and easy maintenance.

[0042] As a further embodiment of the present invention, a wedge block 22 is slidably disposed in the fixing cavity 21, and the fixing cavity 21 has a conical structure that is larger at the top and smaller at the bottom.

[0043] Specifically, during actual processing, when the valve tube end is inserted into the fixed cavity 21, the wedge 22 is initially in an open position. As the sliding plate 3 continues to move downward, the valve tube undergoes plastic deformation under the squeezing action of the slider 43, gradually forming the required constricted shape. During this process, the downward pressure on the valve tube is transmitted to the wedge 22 in the bottom mold 2. As the sliding plate 3 drives the constricting mold 4 downward, the valve tube is subjected to downward pressure, pushing the wedge 22 down along the conical surface of the fixed cavity 21. Since the cone angle of the conical structure of the fixed cavity 21 is 15° to 45° (e.g., Figure 2 As shown, the wedge 22 is forced to converge towards the center as it moves downwards, forming a self-locking clamp on the valve tube, thus preventing damage to the valve tube surface due to excessive friction. Furthermore, the inner surface of the wedge 22 is machined with anti-slip textures, further enhancing clamping stability. This structure achieves automatic clamping of the valve tube through the conical self-locking principle, avoiding the need for an additional power source required by traditional clamps.

[0044] As a further embodiment of the present invention, a fixing rod 41 is fixedly provided on the constriction mold 4, and a support mold 42 for supporting the inside of the valve pipe port is fixedly provided at the bottom end of the fixing rod 41.

[0045] Specifically, the support mold 42 is detachable and is fixed to the bottom end of the fixing rod 41 with bolts (e.g., Figure 2 and Figure 4 (As shown). The shape of the support mold 42 matches the inner diameter of the valve tube, and various specifications are available. Before processing, a suitable support mold 42 is selected according to the inner diameter of the valve tube and fixed to the bottom of the fixing rod 41 with bolts. When the necking process is performed, the support mold 42 extends into the valve tube to provide internal support for the valve tube wall and prevent the valve tube from collapsing or deforming during the necking process.

[0046] As a further embodiment of the present invention, a rotating ring 441 is rotatably provided on the transmission block 44, and a transmission rod 442 is provided between the rotating ring 441 and the slider 43 for transmission connection.

[0047] Specifically, the transmission rod 442 is a rigid connecting rod, with one end hinged to the rotating ring 441 and the other end hinged to the slider 43. When the hydraulic cylinder 51 pushes the transmission block 44 downward, the rotating ring 441 moves downward synchronously with the transmission block 44. Due to the transmission action of the transmission rod 442, the slider 43 expands outward along the radial guide rail of the necking die 4 during the downward movement of the rotating ring 441. There are six sliders 43, which can maintain synchronous movement and ensure that the valve pipe port is uniformly necked.

[0048] As a further embodiment of the present invention, it also includes a plurality of limiting wheels 45 arranged in a circumferential array within the constriction mold 4, and the limiting wheels 45 are flush with the inner wall end face formed by the slider 43 in the default state.

[0049] Specifically, after the slider 43 completes the necking and expands outward, the device enters the pressure holding and shaping stage. The hydraulic cylinder 51 begins to push the transmission block 44 downward, causing it to transition from a high position to a low position. The downward movement of the transmission block 44, through the transmission action of the rotating ring 441 and the transmission rod 442, drives the six sliders 43 to expand outward synchronously along the radial guide rail of the necking mold 4. The limiting wheel 45 then contacts the outer surface of the valve tube port, achieving the effect of pressure holding. Since the limiting wheel 45 can rotate freely, it can adaptively adjust its position according to the slight deformation of the valve tube during the pressure holding process, applying uniform radial pressure to the valve tube port. This design effectively prevents the rebound deformation of the valve tube due to material elasticity, ensuring the stability of the necking dimensions.

[0050] The pressure holding process described above lasts for about 2 to 3 seconds, which is sufficient to allow the valve tube shape to be fully shaped.

[0051] As a further embodiment of the present invention, the reducing die 4 is also provided with a sawtooth structure corresponding to the grinding part 445, and the transmission block 44 and the sawtooth structure are interleaved when the transmission block 44 is in the low position.

[0052] Specifically, a lower locking block 443 is fixedly installed at the lower end of the transmission block 44. In the initial state, the transmission block 44 is in a high position, and the groove of the lower locking block 443 engages with the sawtooth structure to prevent the transmission block 44 from rotating. When the hydraulic cylinder 51 pushes the transmission block 44 down to a low position, firstly, the lower locking block 443 at the lower end of the transmission block 44 completely disengages from the sawtooth structure on the reducing die 4, releasing the rotational constraint on the transmission block 44; secondly, the upper gear 444 at the upper end of the transmission block 44 enters a fully meshed state with the drive gear 521 on the output shaft of the motor 52.

[0053] Furthermore, the motor 52 is started, and through the meshing of the drive gear 521 and the upper gear 444, the entire transmission block 44 and the grinding unit 445 are driven to rotate at a predetermined speed. When the grinding unit 445 performs chamfering on the valve pipe port, its rotational speed, feed force, and processing time can be precisely controlled according to the characteristics of the copper material to ensure a smooth chamfered surface. This mechanical clutch mechanism ensures the safety of the processing; chamfering can only be performed after the necking process is completed, preventing misoperation. It also features a simple and reliable structure and is easy to maintain.

[0054] Working principle:

[0055] The operator first vertically inserts the copper valve tube of the shut-off valve into the fixed cavity 21 of the bottom mold 2, ensuring that the end of the valve tube protrudes to an appropriate length (usually 1.2-1.5 times the length of the constricted end). At this time, the wedge 22 in the fixed cavity 21 is in the initial open state, providing sufficient space for the smooth insertion of the valve tube.

[0056] After clamping, the hydraulic system is activated. Driven by hydraulic pressure, the sliding plate 3 slowly moves downwards along the precision guide rail on the worktable 1, causing the entire necking die 4 assembly to move downwards synchronously. During this stage, the transmission block 44 remains in a high position under the action of the hydraulic cylinder 51. The sliding plate 3 drives the necking die 4 downwards, and the slider 43 remains in the radially contracted position, its inner wall forming a complete necking die cavity. The support die 42 first enters the valve tube to provide internal support for the thin-walled copper valve tube, effectively preventing the tube wall from collapsing or becoming unstable during the subsequent necking process.

[0057] Furthermore, the inner wall of slider 43 contacts the outer surface of the valve tube port, initiating a radial compression action on the valve tube. Then, the inner wall of slider 43 contacts the valve tube port and begins to narrow and form. As the sliding plate 3 continues to move downward, the valve tube undergoes plastic deformation under the compression action of slider 43, gradually forming the desired narrowed shape.

[0058] During this process, the downward pressure on the valve tube is transmitted to the wedge 22 inside the bottom mold 2, pushing the wedge 22 to slide downward along the conical surface of the fixed cavity 21. Because the fixed cavity 21 has a conical structure of 15°-45°, the wedge 22 is forced to converge towards the center as it moves downward, forming a self-locking clamp on the valve tube. This unique clamping mechanism ensures the stable fixation of the valve tube during processing and avoids damage to the copper surface that traditional fixtures may cause.

[0059] After the initial necking is completed, the hydraulic cylinder 51 begins to push the transmission block 44 downward, causing it to switch from a high position to a low position. This drives the slider 43 to expand radially through the transmission rod 442. When the slider 43 is fully expanded, the circumferentially arranged limiting wheels 45 in the necking mold 4 immediately contact the outer surface of the valve tube. The limiting wheels 45 contact the outer wall of the valve tube and maintain pressure to prevent rebound.

[0060] During the pressure holding and shaping process, the transmission block 44 descends to its lowest position, and the grinding section 445 contacts the valve pipe port. Simultaneously, the upper gear 444 meshes with the drive gear 521. The motor 52 starts, driving the grinding section 445 to rotate, which in turn drives the entire transmission block 44 and the grinding section 445 to rotate at a predetermined speed. When the grinding section 445 performs chamfering on the valve pipe port, its rotational speed, feed force, and processing time can be precisely controlled according to the characteristics of the copper material to complete the chamfering process.

[0061] After the chamfering process is completed, motor 52 stops operating first. Then, the hydraulic system executes a reset procedure: hydraulic cylinder 51 pulls transmission block 44 to its highest position, during which transmission rod 442 drives slider 43 to radially retract and reset; simultaneously, sliding plate 3 drives the necking mold 4 to move upwards as a whole, support mold 42 exits from the valve tube, and limit wheel 45 disengages from the valve tube surface. Finally, wedge block 22 returns to its open state, and the operator can remove the processed valve tube.

[0062] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A valve tube processing device for a gate valve, comprising a worktable (1), a bottom mold (2), a necking mold (4), a hydraulic cylinder (51), and a motor (52), characterized in that, The bottom mold (2) has a fixing cavity (21) for fixing the end of the valve tube of the shut-off valve. Multiple sliders (43) are arranged in a circular array within the constriction mold (4). The sliders (43) are slidably arranged on the constriction mold (4) in a radial direction. In the default state, the multiple sliders (43) have the shortest spacing and the inner walls enclose each other to form a constriction mold. A transmission block (44) is axially slidably disposed on a support mold (42), having a high position and a low position disposed opposite to each other, and a transmission rod (442) is provided on the transmission block (44) for driving the slider (43) during the switching of the high and low position states. It also includes a grinding part (445) fixedly disposed at the lower end of the transmission block (44). When the transmission block (44) descends to the low position, the grinding part (445) abuts against the valve pipe port after the narrowing. A motor (52) for driving the transmission block (44) to rotate in the low position state is located on the reducing mold (4); It also includes a hydraulic cylinder (51) mounted on the necking mold (4), which is used to control the lifting and lowering of the transmission block (44); It also includes multiple limiting wheels (45) arranged in a circular array within the constriction mold (4), and the inner wall end face formed by the limiting wheels (45) and the slider (43) in the default state is flush.

2. The valve tube processing device for a gate valve according to claim 1, characterized in that, A wedge (22) is slidably disposed in the fixed cavity (21), and the fixed cavity (21) has a cone-shaped structure that is larger at the top and smaller at the bottom.

3. The valve tube processing device for a stop valve according to claim 1, characterized in that, A fixing rod (41) is fixedly provided on the constriction mold (4), and a support mold (42) for supporting the inside of the valve pipe port is fixedly provided at the bottom end of the fixing rod (41).

4. The valve tube processing device for a gate valve according to claim 1, characterized in that, A rotating ring (441) is rotatably mounted on the transmission block (44), and a transmission rod (442) is provided between the rotating ring (441) and the slider (43) for transmission connection.

5. The valve tube processing device for a stop valve according to claim 1, characterized in that, The reducing die (4) is also provided with a sawtooth structure corresponding to the grinding part (445), and when the transmission block (44) is in a low position, the transmission block (44) and the sawtooth structure are interleaved.

6. The valve tube processing device for a stop valve according to claim 2, characterized in that, The cone angle of the cone-shaped structure of the fixed cavity (21) is 15° to 45°.

7. The valve tube processing apparatus for a gate valve according to claim 1, characterized in that, The transmission rod (442) is a rigid connecting rod, with one end hinged to the rotating ring (441) and the other end hinged to the slider (43).

8. The valve tube processing apparatus for a stop valve according to claim 3, characterized in that, The support mold (42) is detachable and is fixed to the bottom of the fixing rod (41) by bolts.

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