A plunger pair assembly device and method

Abstract

This invention relates to a plunger assembly device, including a ball-wrapping device. The ball-wrapping device includes a guide seat, a fixed half-mold, a movable half-mold, and an elastic element. The guide seat has a boss, and the fixed half-mold and the movable half-mold are located in grooves that mate with the boss. The fixed half-mold and the movable half-mold are arranged opposite to each other. The fixed half-mold has a first cavity, and the movable half-mold has a second cavity. After the fixed half-mold and the movable half-mold are fully fitted, the inner cavity shape formed by the first cavity and the second cavity is consistent with the plunger assembly. The guide seat has a seat hole, which corresponds to the inner cavity, and the elastic element is disposed in the seat hole. The plunger assembly device and method of this invention can greatly improve the operability and stability of the plunger assembly ball-wrapping device, simplify the ball-wrapping process, and reduce manufacturing costs.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of micro hydraulic plunger pump, in particular to a plunger pair assembling device and method. BACKGROUND

[0002] At present, the micro hydraulic plunger pump technology develops rapidly in China, and is widely used in various occasions with very limited space, volume and weight. Because the volume and displacement of the micro hydraulic plunger pump are small, the size of the plunger pair is also very small. The traditional "pressing and loosening device" cannot meet the requirements, and a simple, reliable and easy-to-operate ball packing assembly is needed to meet the ball packing needs of the small-size plunger pair.

[0003] The ball packing process of the driven plunger pair usually adopts the pressing and loosening process means, which requires a set of pressing device and a set of loosening device. The pressing device adopts the split type, the inner hole is processed as a spherical surface, and the hydraulic press is used for pressing to make the sliding shoe fit the spherical surface in the inner hole during the downward movement, and the sliding shoe is deformed under the action of the spherical surface to make the inner spherical surface of the sliding shoe tightly fit. After the ball is packed by the press-down type, the plunger and the sliding shoe cannot rotate, and the loosening device of the equipment must be used to extrude the outer circular port of the sliding shoe to make the sliding shoe deform slightly again, and the plunger and the sliding shoe can rotate flexibly after being loosened. However, this method is not suitable for the ball packing of the plunger pair of the micro plunger pump. The sliding shoe of the micro plunger pump is small and thin, and is easy to deform or break under the press-down of the hydraulic press, resulting in scrap parts.

[0004] In addition, there is a simple split type ball packing device composed of adjusting gasket, sleeve, positioning ring, spring sleeve, bottom plate, spring seat and spring. This structure is relatively complex, and when packing the ball, the sliding shoe is downward, the plunger is downward by the press, until the press contacts the adjusting gasket, and then the ball packing effect is checked. If the ball packing effect is not good, the thickness of the adjusting gasket needs to be changed, and the plunger is reassembled until the ball packing effect is good. If the gasket is too thin at first, the plunger ball head may deform the sliding shoe ball socket when the plunger is pressed too much, and if the gasket is too thick, the gap between the plunger and the sliding shoe will be large. This method is relatively complex to operate, and the thickness of the adjusting gasket is required to be high. However, during the machining process, there are individual differences in the size of the plunger and the sliding shoe. If the adjusting gasket is not selected properly, the sliding shoe may be damaged or the ball packing may not be tight, which may affect the service life of the plunger pair. Moreover, because the adjusting gasket needs to be replaced constantly, it is not suitable for mass production and lacks stability. SUMMARY

[0005] In order to solve the problems of the prior art, the present application provides a plunger pair assembling device and method which has high consistency of ball packing effect and is simple and convenient to operate.

[0006] The specific technical solutions are as follows: a plunger pair assembly device, comprising a ball wrapping device, the ball wrapping device comprising a guide seat, a fixed half mold, a movable half mold and an elastic member, the guide seat being provided with a boss, the fixed half mold and the movable half mold being arranged in a groove matched with the boss, the fixed half mold and the movable half mold being oppositely arranged, the fixed half mold having a first cavity, the movable half mold having a second cavity, the inner cavity formed by the first cavity and the second cavity being consistent with the plunger pair after the fixed half mold and the movable half mold are completely attached, the guide seat having a seat hole, the seat hole being arranged corresponding to the inner cavity, and the elastic member being arranged in the seat hole.

[0007] As a preferred technical solution, the boss is a T-shaped boss, and the groove is a T-shaped groove.

[0008] As a preferred technical solution, the boss is at least two, and the number of grooves of the fixed half mold and the movable half mold is the same as the number of bosses.

[0009] As a preferred technical solution, the fixed half mold is fixedly connected with the guide seat.

[0010] As a preferred technical solution, the first cavity and the second cavity are symmetrically arranged, and the first cavity and the second cavity are arranged on the vertical planes of the fixed half mold and the movable half mold respectively, and the groove is arranged on the horizontal bottom surface of the fixed half mold and the movable half mold.

[0011] As a preferred technical solution, the guide seat is arranged on the clamp, and the clamp jaw drives the movable half mold.

[0012] As a preferred technical solution, a main shaft is arranged above the fixed half mold.

[0013] As a preferred technical solution, the guide seat, the fixed half mold and the movable half mold are subjected to vacuum quenching treatment, so that the hardness reaches HRC58-62, each surface of the guide seat is subjected to grinding processing, the groove is subjected to precise numerical control slow wire cutting processing, the surface roughness reaches Ra0.4, and the tolerance is controlled within 0-0.005.

[0014] A use method of a plunger pair assembly device, comprising the following steps:

[0015] S100: placing the ball wrapping device on the clamp plane, and tightly attaching the fixed half mold to the jaw;

[0016] S200: placing the clamp and the fixed half mold on the bench drill platform, roughly aligning the ball wrapping device hole with the bench drill main shaft, and fixing the clamp;

[0017] S300: pulling the movable half mold to a suitable position, placing the plunger into the ball wrapping device hole, placing the sliding shoe into the upper end of the ball wrapping device hole, and making the inner end surface of the sliding shoe flush with the inner end surface of the hole stop;

[0018] S400: move the movable half mold, so that the movable half mold slides along the T-shaped boss to the center and tightly contacts the outer circle of the sliding shoe;

[0019] S500: fasten the clamp, slowly force the movable half mold to move to the center.

[0020] As a preferred technical solution, after step S500, the two parallel pressing blocks are placed on the fixed half mold plane, the operating table drill main shaft is pressed down until the pressing block is pressed to completely match the fixed half mold plane; the clamp is pulled again, slowly forced until the movable half mold and the fixed half mold plane completely match; the clamp is loosened, the movable half mold is removed, and the wrapped plunger pair is taken out of the device.

[0021] The technical effect of the present application: the plunger pair assembly device and method of the present application can greatly improve the operability and stability of the plunger pair wrapping ball, simplify the process flow of the wrapping ball, and reduce the manufacturing cost. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a schematic diagram of a plunger pair assembly device of an embodiment of the present application.

[0023] Figure 2 is another schematic diagram of a plunger pair assembly device of an embodiment of the present application.

[0024] Figure 3 is a schematic diagram of a guide seat of an embodiment of the present application.

[0025] Figure 4 is a schematic diagram of a fixed half mold of an embodiment of the present application.

[0026] Figure 5 is a schematic diagram of a movable half mold of an embodiment of the present application.

[0027] Figure 6 is a schematic diagram of a clamp of an embodiment of the present application.

[0028] Figure 7 is a schematic diagram of a pressing block of an embodiment of the present application. Figure 6 is an enlarged view of part A of the present application.

[0029] Figure 8 is a schematic diagram of a pressing block of an embodiment of the present application. DETAILED DESCRIPTION

[0030] In the following, the essential features and advantages of the present application will be further described in conjunction with examples, but the present application is not limited to the listed embodiments.

[0031] For example, Figures 1 to 7As shown, this embodiment of a plunger assembly device includes a ball-wrapping device 100, which includes a guide seat 1, a fixed half-mold 2, a movable half-mold 3, and an elastic element 4. The guide seat 1 has a boss 11, and the fixed half-mold 2 and the movable half-mold 3 are disposed in a groove 20 that mates with the boss 11. The fixed half-mold 2 and the movable half-mold 3 are arranged opposite to each other. The fixed half-mold 2 has a first cavity 21, and the movable half-mold 3 has a second cavity 31. After the fixed half-mold 21 and the movable half-mold 31 are fully fitted, the shape of the inner cavity 5 formed by the first cavity 21 and the second cavity 31 is consistent with that of the plunger assembly 6. The hole 51 of the inner cavity 5 is located at the top of the ball-wrapping device 100. The guide seat 1 has a seat hole 12, which is correspondingly arranged with the inner cavity 5. The elastic element 4 is disposed in the seat hole. In the above technical solution, the guide seat is used for positioning and centering. In this embodiment, the boss is a T-shaped boss, and the groove is a T-shaped groove. The fixed half-mold and movable half-mold are designed with T-slots and guide seat T-shaped bosses as a mating pair, serving a self-centering function. The fixed half-mold 2 is fixedly connected to the guide seat 1 and is pressed and fixed to the guide seat 1 with screws. The movable half-mold 3 is positioned by the T-shaped groove and can slide smoothly along the guide seat 1 until it is completely in contact with the plane of the fixed half-mold. The seat hole in the middle of the guide seat is for installing an elastic element. In this embodiment, the elastic element is a pre-tension spring. After the fixed half-mold and movable half-mold are completely in contact, the inner cavity formed is consistent with the plunger pair. When wrapping the ball, the pre-tension spring is installed in the seat hole of the guide seat, and the plunger 10 and the slipper 30 are respectively placed into the inner cavity 5. The lower end face of the plunger 10 is in contact with the upper end face of the spring. The pre-tension spring has an upward pre-tensioning effect. The plunger 10 is pushed upward by the spring, and the ball head is always in contact with the ball socket of the slipper 30. Apply force slowly, causing the movable half-die to move along the boss of the guide seat, gradually approaching the center. Under the clamping force, the outer lateral force of the slide shoe's ball socket and the clamping of the two half-die's ball sockets gradually deform and close. At this time, the pre-tension spring always provides an upward force to the plunger, ensuring that the plunger ball head remains in contact with the slide shoe's ball socket and will not move downwards or detach from the slide shoe. Through the above technical solution, the slide shoe and plunger are not subjected to hydraulic pressure during the entire ball-wrapping process, and due to good positioning, the slide shoe surface will not deform under stress, resulting in a high success rate of ball wrapping. After wrapping, simply hold the plunger and shake it for a moment to allow it to rotate freely, eliminating the need for a ball-releasing device. Furthermore, the gap is within 0.01-0.02mm.

[0032] In this embodiment, there are at least two bosses 11. The number of grooves on the fixed half-mold 2 and the movable half-mold 3 is the same as the number of bosses, thereby making the movement of the movable half-mold smoother. This embodiment provides two bosses. The first cavity 21 and the second cavity 31 are symmetrically arranged. The first cavity 21 and the second cavity 31 are respectively arranged on the vertical plane 22 of the fixed half-mold 2 and the movable half-mold 3. The first cavity and the second cavity are integrally formed with the fixed half-mold and the movable half-mold. The groove 20 is arranged on the horizontal bottom surface 23 of the fixed half-mold and the movable half-mold. The guide seat 1 is arranged on the clamp 7, and the clamp 71 of the clamp 7 drives the movable half-mold 3. A pressure shaft 8 is provided above the fixed half-mold 2. In this embodiment, the clamp is a precision vise, and the pressure shaft is the spindle of a bench drill 200. The precision vise is used to clamp the fixed half-mold 2 and the movable half-mold 3 and the vise is placed on the bench drill platform with its center roughly aligned with the bench drill spindle. During the clamping process, the slipper may move upward. Place the two parallel pressure blocks on the upper surface of the half mold, manually operate the bench drill spindle to press down until the pressure blocks are completely in contact with the upper surface of the half mold. Then, turn the vise again and slowly apply force until the movable half mold is completely in contact with the fixed half mold surface. Release the vise and remove the wrapped plunger assembly from the device.

[0033] Furthermore, to achieve a better ball-wrapping effect, the guide seat 1, fixed half-mold 2, and movable half-mold 3 are all vacuum hardened to achieve a hardness of HRC58-62. The guide seat 1 is ground on all surfaces, and the grooves are machined using precision CNC wire cutting, achieving a surface roughness of Ra0.4 with a tolerance controlled within 0-0.005. The fixed half-mold and movable half-mold are machined as a single unit before hardening, with pre-drilled inner holes leaving a 0.5mm allowance. After hardening, all planes are precision ground, then wire-cut from the middle, and the planes are finely ground. After assembling the fixed half-mold and movable half-mold, a T-slot is precisely cut using wire cutting, achieving a surface roughness of Ra0.4 with a groove tolerance controlled within +0.005-+0.01, ensuring a clearance of 0.005-0.01mm with the T-shaped boss of the guide seat. Then, the fixed half mold and the movable half mold are installed on the guide seat, and the inner spherical surface is machined by electrical discharge machining using a precision electrical discharge machine to ensure that its roughness Ra0.4 and the gap between the inner spherical diameter and the outer circle of the chemical ball socket is 0.008-0.012mm.

[0034] A method for using a plunger assembly device includes the following steps: S100: Place the ball-wrapping device 100 on the plane of the clamp 7, and fix the half-die tightly against the jaw 72; S200: Place the clamp 7 and the fixed half-die 2 on the platform of the bench drill 200, so that the hole of the ball-wrapping device 100 is roughly aligned with the spindle of the bench drill, and fix the clamp; S300: Pull the movable half-die 3 to a suitable position, put the plunger 10 into the hole of the ball-wrapping device with the plunger ball head facing upward, and put the slipper into the upper end of the hole of the ball-wrapping device, so that the inner end face of the slipper is flush with the inner end face of the hole stop; S400: Move the movable half-die 3 so that the movable half-die 3 slides along the T-shaped boss towards the center and is close to the outer circle of the slipper; S500: Tighten the clamp and slowly apply force to move the movable half-die towards the center. Through the above technical solution, under the clamping force, the outer circle of the sliding shoe ball socket gradually deforms and closes under the clamping force of the two half mold ball sockets. At this time, the pre-tightening spring always gives the plunger an upward pre-tightening force, so that the plunger ball head fits with the sliding shoe ball socket.

[0035] During the clamping process, if the slipper moves upward, after step S500, the two parallel pressure blocks 40 (such as...) Figure 8 (As shown) Place it on the upper surface of the fixed half mold 2, operate the bench drill spindle to press down until the pressure block is completely in contact with the upper surface of the fixed half mold; move the clamp again and slowly apply force until the movable half mold is completely in contact with the plane of the fixed half mold; release the clamp, remove the movable half mold, and take the wrapped plunger pair out of the device.

[0036] This embodiment presents a plunger assembly device and method that is simple to operate, reliable, and low in cost. It is applicable to the ball-wrapping device for plunger assemblies in micro plunger pumps with plunger diameters of Φ10mm or less. It solves the technical problem of existing press-fit ball-wrapping fixtures easily damaging the slipper end face, effectively improving parts utilization and efficiency, and enhancing economic efficiency.

[0037] It should be noted that the above preferred embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A plunger assembly device, characterized in that, The device includes a ball-wrapping assembly, comprising a guide seat, a fixed half-mold, a movable half-mold, and an elastic element. The guide seat has a boss, and the fixed and movable half-molds are located in grooves that mate with the boss. The fixed and movable half-molds are arranged opposite to each other. The fixed half-mold has a first cavity, and the movable half-mold has a second cavity. After the fixed and movable half-molds are fully fitted, the inner cavity shape formed by the first and second cavities conforms to the shape of the plunger pair. The guide seat has a seat hole corresponding to the inner cavity, and the elastic element is disposed within the seat hole. The first and second cavities are symmetrically arranged, and the first and second cavities respectively... The groove is set on the vertical plane of the fixed half mold and the movable half mold. The groove is set on the horizontal bottom surface of the fixed half mold and the movable half mold. A main shaft is set above the fixed half mold. Two parallel pressure blocks are set on the upper plane of the fixed half mold. The inner end face of the slipper is flush with the inner end face of the hole stop of the ball wrapping device. When wrapping the ball, the guide seat is set on the clamp. The clamp of the clamp drives the movable half mold. Under the lateral force of the outer circle of the slipper ball socket and the clamping of the ball sockets of the two half molds, the movable half mold gradually deforms and closes. The main shaft presses down until the pressure block is pressed to be completely flush with the upper plane of the fixed half mold. The clamp is moved again until the movable half mold is completely flush with the plane of the fixed half mold.

2. The plunger assembly device according to claim 1, characterized in that, The boss is a T-shaped boss, and the groove is a T-shaped groove.

3. The plunger assembly device according to claim 2, characterized in that, There are at least two bosses, and the number of grooves in the fixed half-mold and the movable half-mold is the same as the number of bosses.

4. The plunger assembly device according to claim 1, characterized in that, The fixed half-mold is fixedly connected to the guide seat.

5. The plunger assembly device according to claim 1, characterized in that, The guide seat, fixed half mold, and movable half mold are all vacuum hardened to achieve a hardness of HRC58-62. The guide seat is ground on all sides, and the groove is machined by precision CNC wire cutting to achieve a surface roughness of Ra0.4 with a tolerance of 0-0.

005.

6. A method of using a plunger assembly device, characterized in that, The plunger assembly device according to any one of claims 1 to 5 includes the following steps: S100: Place the ball-wrapping device on the clamp plane and fix the half mold tightly against the jaws; S200: Place the fixture and fixed half mold on the bench drill platform, roughly align the ball-wrapping device hole with the bench drill spindle, and fix the fixture; S300: Pull the movable half mold to the appropriate position, put the plunger into the ball-wrapping device hole with the plunger ball head facing upward, put the slipper into the upper end of the ball-wrapping device hole, so that the inner end face of the slipper is flush with the inner end face of the hole stop. S400: Move the movable half mold so that it slides along the T-shaped boss towards the center and fits tightly against the outer circle of the slip shoe; S500: Tighten the clamp and apply force slowly to move the movable half mold towards the center.

7. The method of using the plunger assembly device according to claim 6, characterized in that, After step S500, place the two parallel pressure blocks on the upper surface of the fixed half mold, and operate the bench drill spindle to press down until the pressure blocks are completely in contact with the upper surface of the fixed half mold; then move the clamp again and slowly apply force until the movable half mold is completely in contact with the plane of the fixed half mold; release the clamp, remove the movable half mold, and take the wrapped plunger assembly out of the device.

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