Rolling ejector pin
The rolling ejector pin design, which combines large and small balls, solves the problem of insufficient strength of existing ejector pins, enabling it to withstand larger axial and radial loads, improving machining accuracy and service life, and making it suitable for use in confined spaces.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-10
- Publication Date
- 2026-03-31
AI Technical Summary
Existing ejector pins are typically designed with a pointed, conical shape at the end, resulting in poor strength and an inability to withstand large pushing loads. Consequently, they cannot simultaneously withstand large axial and radial loads during the manufacturing process.
The system employs a combination of large and small balls. The large ball acts as the main force-bearing component, while multiple small balls decompose and disperse the axial force radially. This force is then transmitted to the main body during rolling, achieving the decomposition and dispersion of both axial and radial forces. Combined with the fixed connection between the top cover and the main body, this ensures the stable rolling of both the large and small balls.
It improves the strength and service life of the ejector pin, enabling it to withstand larger axial and radial loads, reduce frictional heat, adapt to use in confined spaces, and ensure machining accuracy and consistency.
Smart Images
Figure CN224058735U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of ejector pins, specifically to a rolling ejector pin. Background Technology
[0002] Ejector centers are commonly used in machine tool processing, especially for precision parts that require multiple machining operations. Their main function is to hold the workpiece in a specific position, ensuring that its relative position remains constant during subsequent machining processes. This guarantees machining accuracy and consistency. During machining, ejector centers help maintain a stable position on the machine tool, preventing machining errors caused by workpiece loosening or displacement. Therefore, using ejector centers improves the overall accuracy and quality of the product.
[0003] Common types of ejector pins include those with tapered or cylindrical tips. These pins can be inserted into the positioning holes of a workpiece to achieve positioning and fixation through contact with the workpiece. They are typically mounted on the worktable, fixture, or mold of machining equipment and are generally used in conjunction with fixtures, chucks, and other fixing tools to ensure that the workpiece does not shift during machining.
[0004] However, existing ejector pins are usually designed with a pointed cone shape at the end, which makes them weak and unable to withstand large pushing loads. Therefore, ejector pins usually only have a positioning function and do not have a pushing function. Utility Model Content
[0005] The purpose of this invention is to provide a rolling ejector pin that can withstand a large axial load while also bearing a certain radial load through the combination of a large ball and a small ball.
[0006] To achieve the above objectives, this utility model provides a rolling ejector pin, which includes a body, a large ball, and small balls. Multiple small balls are provided and embedded inside the body. The bottom of the large ball is embedded inside the body, and the large ball protrudes at least partially from the top of the body.
[0007] The upper surfaces of the multiple small balls form a rolling plane, and the bottom of the large ball rolls along the rolling plane. During the rolling process, the center position of the large ball remains unchanged.
[0008] Preferably, the body includes a main body and a top cover, the top cover being fixedly connected to the main body for sealing the large ball and the small ball;
[0009] The top cover is provided with a through hole, and the portion of the large ball protruding from the body extends out through the through hole. The diameter of the through hole is smaller than the maximum diameter of the large ball.
[0010] Preferably, the diameter of the through hole is the same as the diameter of the cross-sectional circle at the connection between the large sphere and the top cover.
[0011] Preferably, the top of the main body is recessed inward to form a spherical support surface, and a plurality of small spheres fill the space between the spherical support surface and the large sphere.
[0012] Preferably, a connector is provided at the bottom of the main body, and the rolling ejector pin is fixedly connected to the machining equipment through the connector.
[0013] Preferably, the top cover is provided with an internal thread, and the position where the main body connects to the top cover is provided with an external thread, and the top cover is screwed to the main body.
[0014] Preferably, the top cover and the main body are provided with an anti-loosening treatment.
[0015] According to the above technical solution, the end of the rolling ejector pin of this utility model is set as a large ball. When a large axial force is applied, the large ball, as the main force-bearing body, can exhibit good strength. At the same time, the large ball transmits these axial forces to multiple small balls below. The multiple small balls decompose the axial force along their respective radial directions and finally transmit it to the main body. Therefore, through the cooperation of the large ball and multiple small balls, the axial force on the rolling ejector pin is decomposed and dispersed. Thus, through the cooperation of the large ball and multiple small balls, the rolling ejector pin can withstand a large axial load.
[0016] The upper surfaces of multiple small balls form a rolling plane, on which a large ball is placed. When the large ball of the rolling ejector pin is subjected to a radial force, it will roll around its center under the action of this radial force. As the large ball rolls, the small balls located below it to support it will also roll along with it. Similarly, the multiple small balls in rolling contact with the large ball can decompose and disperse the radial force, and transfer this radial force to the main body, thus achieving reliable bearing of the radial force on the rolling ejector pin. Moreover, throughout the entire process, there is rolling friction between the large and small balls, and between the small balls and the main body. The frictional force is small, the rolling ejector pin moves smoothly, and no significant frictional heat is generated, which can effectively improve the service life of the rolling ejector pin.
[0017] To accommodate confined workspaces, the diameter of the rolling ejector pin can be set slightly larger than the diameter of the large ball, allowing the rolling ejector pin to achieve a smaller volume and still function in narrow spaces.
[0018] In the above process, since the rolling ejector pin is usually a rod, the axial force on the body is significantly better than the radial force. Therefore, in actual use, this rolling ejector pin can withstand a large axial force while also withstanding a certain radial force.
[0019] Since the radial force ultimately acts on the sidewall of the body that contacts the small ball, the structural strength of the sidewall is an important factor affecting the radial force on the rolling ejector pin. Therefore, when the difference between the diameter of the body and the diameter of the large ball is large, the rolling ejector pin can withstand a larger radial force; when the difference between the diameter of the body and the diameter of the large ball is small, the rolling ejector pin can withstand a smaller radial force.
[0020] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description
[0021] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the following detailed description to explain the present invention, but do not constitute a limitation thereof. In the drawings:
[0022] Figure 1 This is a schematic diagram of a rolling ejector pin.
[0023] Explanation of reference numerals in the attached figures
[0024] 4 small balls and 3 large balls
[0025] 1 main body 2 top cover
[0026] 5 connectors Detailed Implementation
[0027] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.
[0028] In this utility model, unless otherwise stated, directional terms such as "embedded," "bottom," "inner," "protruding," "top," and "upper surface" contained in the terminology only represent the orientation of the term in its conventional use or are common terms understood by those skilled in the art, and should not be regarded as limitations on the terminology.
[0029] See Figure 1 The aforementioned rolling ejector pin includes a body, a large ball 3, and small balls 4. Multiple small balls 4 are provided and embedded inside the body. The bottom of the large ball 3 is embedded inside the body, and the large ball 3 protrudes at least partially from the top of the body.
[0030] The upper surfaces of multiple small balls 4 form a rolling plane, and the bottom of the large ball 3 rolls along the rolling plane. During the rolling process, the center position of the large ball 3 remains unchanged.
[0031] Through the implementation of the above technical solution, the end of the rolling ejector pin is configured as a large ball 3. When a large axial force is applied, the large ball 3 acts as the main force-bearing component, exhibiting good strength. Simultaneously, the large ball 3 transmits this axial force to multiple smaller balls 4 below. The smaller balls 4 decompose the axial force along their respective radial directions and ultimately transmit it to the main body. Therefore, by combining the large ball 3 with the multiple smaller balls 4, the axial force on the rolling ejector pin is decomposed and dispersed. Consequently, through this combination, the rolling ejector pin can withstand a large axial load.
[0032] The upper surfaces of multiple small balls 4 form a rolling plane, on which a large ball 3 is placed. When the large ball 3 of the rolling ejector pin is subjected to a radial force, it will roll around its center under the action of this radial force. As the large ball 3 rolls, the small balls 4 located below it to support it will also roll along with it. Similarly, the multiple small balls 4 in rolling contact with the large ball 3 can decompose and disperse the radial force and transfer it to the main body, thus achieving reliable bearing of the radial force on the rolling ejector pin. Moreover, throughout the process, there is rolling friction between the large ball 3 and the small balls 4, and between the small balls 4 and the main body. The friction is small, the rolling ejector pin moves smoothly, and no significant frictional heat is generated, which can effectively improve the service life of the rolling ejector pin.
[0033] To accommodate confined workspaces, the diameter of the rolling ejector pin can be set slightly larger than the diameter of the large ball 3, allowing the rolling ejector pin to achieve a smaller volume while still being usable in narrow spaces.
[0034] In the above process, since the rolling ejector pin is usually a rod, the axial force on the body is significantly better than the radial force. Therefore, in actual use, this rolling ejector pin can withstand a large axial force while also withstanding a certain radial force.
[0035] Since the radial force will eventually act on the sidewall of the body that contacts the small ball 4, the structural strength of the sidewall is an important factor affecting the radial force on the rolling ejector. Therefore, when the difference between the diameter of the body and the diameter of the large ball 3 is large, the radial force that the rolling ejector can withstand is large; when the difference between the diameter of the body and the diameter of the large ball 3 is small, the radial force that the rolling ejector can withstand is small.
[0036] In this manner, preferably, the body includes a main body 1 and a top cover 2, the top cover 2 being fixedly connected to the main body 1 for sealing the large ball 3 and the small ball 4;
[0037] The top cover 2 is provided with a through hole, and the part of the large ball 3 that protrudes from the body extends out through the through hole. The diameter of the through hole is smaller than the maximum diameter of the large ball 3.
[0038] Since the diameter of the through hole is smaller than the maximum diameter of the large ball 3, after the rolling ejector pin is installed, when the large ball 3 attempts to come out of the main body 1, the maximum diameter of the large ball 3 interferes with the through hole. Thus, under the blocking effect of the top cover 2, the large ball 3 can maintain the stability of its relative position with the main body 1.
[0039] The large ball 3 and the small balls 4 can be reliably fixed by the fixed connection between the top cover 2 and the main body 1. The large ball 3 and multiple small balls 4 are located between the main body 1 and the top cover 2. The maximum diameter of the large ball 3 is located below the top cover 2. After the rolling ejector pin is installed, the top cover 2 can cooperate with a certain outer circular section of the large ball 3 to restrict the position of the large ball 3. By restricting the position of the large ball 3, the distance between the large ball 3 and the top of the main body 1 is kept fixed, so that the small balls 4 located between the bottom of the large ball 3 and the top of the main body 1 only have the freedom of rolling.
[0040] In this embodiment, preferably, the diameter of the hole is the same as the diameter of the cross-sectional circle at the connection between the large ball 3 and the top cover 2.
[0041] The diameter of the through hole is set to be the same as the diameter of the cross-sectional circle at the connection between the large ball 3 and the top cover 2, so that the large ball 3 has only the degree of freedom of rotation between the top cover 2 and the main body 1, and cannot be translated in the horizontal plane or moved in the vertical direction.
[0042] When the large ball 3 only has rotational freedom, the small ball 4 located at the bottom of the large ball 3 cannot move in the vertical direction.
[0043] Therefore, by setting the diameter of the through hole to be the same as the diameter of the cross-sectional circle at the connection between the large ball 3 and the top cover 2, both the large ball 3 and the small ball 4 can only roll, which can reduce the friction during the movement and greatly reduce the phenomenon of heat generation during use, thus improving the service life of the rolling ejector pin.
[0044] Preferably, adding lubricant to the rolling ejector pin can further reduce friction during use, enabling the large ball 3 and the small ball 4 to roll more smoothly, and further improving the reliable operation of the rolling ejector pin.
[0045] In this embodiment, preferably, the top of the main body 1 is recessed inward to form a spherical support surface, and a plurality of small balls 4 fill the space between the spherical support surface and the large ball 3.
[0046] The spherical support surface has the same surface curvature as the large sphere 3. Preferably, the radius of the spherical support surface is equal to the diameter of the small sphere 4 and the radius of the large sphere 3. This ensures that all the small spheres 4 located on the spherical support surface can contact the surface of the large sphere 3. When the large sphere 3 is subjected to external forces, these small spheres 4 can reliably bear the force of the large sphere 3 and effectively decompose and disperse these loads.
[0047] Multiple small balls 4 are filled between the spherical support surface and the large ball 3. By reasonably setting the number of small balls 4, the small balls 4 can fill the space between the spherical support surface and the large ball 3, so that there are as many small balls 4 as possible on the spherical support surface to distribute the force on the large ball 3. At the same time, it also ensures that all the small balls 4 have no space to slide and can only roll between the large ball 3 and the spherical support surface.
[0048] In this embodiment, preferably, a connector 5 is provided at the bottom of the main body 1, and the rolling ejector pin is fixedly connected to the machining equipment through the connector 5.
[0049] To facilitate the fixing of the rolling ejector pin to the machining equipment, a connector 5 is provided at the bottom of the main body 1. Through this connector 5, the rolling ejector pin can be easily connected to the machining equipment.
[0050] In one embodiment, the outer surface of the connector 5 is provided with threads, and a reliable connection between the rolling ejector pin and the machining equipment can be achieved by providing threaded holes on the machining equipment.
[0051] In another embodiment, the connector 5 is configured as a flange, through which a reliable connection between the rolling ejector pin and the machining equipment can also be achieved.
[0052] In this embodiment, preferably, the top cover 2 is provided with an internal thread, and the position where the main body 1 is connected to the top cover 2 is provided with an external thread, and the top cover 2 is screwed to the main body 1.
[0053] The top cover 2 is provided with internal threads and is screwed to the main body 1. By continuously screwing the top cover 2 downwards until the large ball 3 restricts the further downward movement of the top cover 2, the position of the large ball 3 can be reliably limited by the top cover 2.
[0054] In this embodiment, preferably, an anti-loosening treatment is provided between the top cover 2 and the main body 1.
[0055] During use, if the relative position of the top cover 2 and the main body 1 changes, for example, if the screw connection between the top cover 2 and the main body 1 becomes loose, the relative position of the large ball 3 and the main body 1 may change, and the large ball 3 may exhibit movements other than rolling. For example, the large ball 3 may bounce during use. Once this happens, it may affect the positioning effect of the rolling ejector pin, and on the other hand, it may worsen the stress on the rolling ejector pin, affecting its service life.
[0056] Therefore, it is necessary to prevent loosening between the top cover 2 and the main body 1. One implementation method is to drip some fast-curing glue into the top cover 2 when screwing it into the main body 1. After the top cover 2 is screwed into the required position, the glue between the top cover 2 and the main body 1 will solidify by maintaining the position of the top cover 2. The solidified glue can achieve an adhesive effect between the top cover 2 and the main body 1, thereby preventing the position of the top cover 2 and the main body 1 from loosening.
[0057] Another implementation method is that after the top cover 2 is screwed into the appropriate position, spot welding can be performed between the top tube and the main body 1 to maintain the position between the top cover 2 and the main body 1.
[0058] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.
[0059] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.
[0060] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.
Claims
1. A rolling plunger characterized by, The rolling plunger comprises a body, a big ball (3) and a plurality of small balls (4), the small balls (4) are embedded in the body, the bottom of the big ball (3) is embedded in the body, and the big ball (3) is at least partially protruded from the top of the body. The upper surfaces of the small balls (4) form a rolling plane, the bottom of the big ball (3) rolls along the rolling plane, and the center of the big ball (3) is fixed during rolling.
2. The rolling plunger as set forth in claim 1, wherein The body comprises a main body (12) and a top cover (2), the top cover (2) is fixedly connected with the main body (12) to seal the big ball (3) and the small balls (4). The top cover (2) is provided with a through hole, the part of the big ball (3) protruding from the body is extended by the through hole, and the diameter of the through hole is smaller than the maximum diameter of the big ball (3).
3. The rolling plunger as set forth in claim 2, wherein The diameter of the through hole is the same as the diameter of the cross section circle at the connection between the big ball (3) and the top cover (2).
4. The rolling plunger as set forth in claim 2, wherein The top of the main body (12) is inwardly recessed to form a spherical supporting surface, and the small balls (4) are filled between the spherical supporting surface and the big ball (3).
5. The rolling plunger as set forth in claim 2, wherein The bottom of the main body (12) is provided with a connecting piece (5), and the rolling plunger is fixedly connected with a machining equipment through the connecting piece (5).
6. The rolling plunger as set forth in claim 2, wherein The top cover (2) is provided with an internal thread, the position where the main body (12) is connected with the top cover (2) is provided with an external thread, and the top cover (2) is screwed with the main body (12).
7. The rolling plunger as set forth in claim 6, wherein The top cover (2) and the main body (12) are provided with anti-loosening treatment.