Cylinder

Abstract

The present invention provides an oil cylinder for use in a hot runner system and fixed to a manifold therein, comprising: a cylinder barrel having a through hole extending therethrough; a base connected to the lower end of the cylinder barrel and having a first clearance hole extending therethrough, the first clearance hole being connected to the through hole; a first piston disposed within the through hole and the first clearance hole and reciprocating along the axial direction of the through hole and the first clearance hole, the first piston being a hollow structure; and a second piston fixedly disposed axially within the first piston to reciprocate along the aforementioned axial direction with the first piston, wherein a floating gap is provided between the first and second pistons in a radial direction perpendicular to the axial direction, so that the second piston can move radially within a certain floating space under the action of an external force, and a valve needle hanging platform is provided within the second piston. This can solve the problem in the prior art that the valve needle is easily bent during reciprocating motion.

Description

Technical Field

[0001] The present invention relates to the technical field of hot runner systems, and in particular to an oil cylinder. Background Art

[0002] Currently, many hot runner systems use a hydraulic cylinder to drive the valve needle to seal the glue. In the hydraulic cylinder, there is usually only a piston that reciprocates within the cylinder barrel, thereby driving the valve needle to reciprocate and seal the glue. However, in hot runner systems, the manifold is very hot, and its thermal expansion and contraction can cause the position of the hole through which the valve needle passes to shift. Since the hydraulic cylinder is at room temperature and the valve needle is fixed to the valve needle mounting plate, the valve needle's position does not change. This situation can easily cause the valve needle to tilt, and since the valve needle needs to reciprocate, it can easily become stuck or bend, thus affecting the glue seal. Summary of the Invention

[0003] The object of the present invention is to provide an oil cylinder, which solves the problem in the prior art that a valve needle is easily bent during reciprocating motion, and realizes stable sealing of the valve needle.

[0004] In order to achieve the above-mentioned purpose of the invention, one embodiment of the present invention provides an oil cylinder, which is used in a hot runner system and fixed on the diverter plate therein, and is characterized in that it includes: a cylinder barrel, which is penetrated by a through hole; a base, which is connected to the lower end of the cylinder barrel and is penetrated by a first give way hole, and the first give way hole is connected to the through hole; a first piston, which is arranged in the through hole and the first give way hole, and reciprocates along the axial direction of the through hole and the first give way hole, and the first piston is a hollow structure; a second piston, which is fixedly arranged in the first piston along the axial direction to reciprocate along the aforementioned axial direction with the first piston, wherein the first piston and the second piston are provided with a floating gap in the radial direction perpendicular to the axis, so that the second piston can move radially in a certain floating space under the action of external force, and a valve needle hanging platform is provided in the second piston.

[0005] As a further improvement of one embodiment of the present invention, the first piston is formed with an inner wall, and a first protrusion is provided on the inner wall; the second piston is formed with an outer wall, and a second protrusion and a fixing structure are provided on the outer wall; the first protrusion is cooperatedly arranged between the second protrusion and the fixing structure; the first protrusion is spaced apart from the outer wall of the second piston; the second protrusion and the fixing structure are spaced apart from the inner wall of the first piston.

[0006] As a further improvement of one embodiment of the present invention, the fixing structure is a retaining ring, a retaining spring and an annular groove arranged on the outer wall of the second piston, the retaining ring is arranged on the first protrusion, the setting position of the annular groove matches the retaining ring, and the retaining spring is arranged in the annular groove and presses against the retaining ring.

[0007] As a further improvement of one embodiment of the present invention, it also includes a support seat, the lower end of the support seat is fixed to the diverter plate, the support seat includes a main body, a second clearance hole arranged on the main body and a limiting portion extending upward along the second clearance hole on the main body, the limiting portion extends into the first piston from the lower end of the first piston, the second piston is arranged in the limiting portion, and a floating gap is provided between the second piston and the limiting portion in the aforementioned radial direction.

[0008] As a further improvement of one embodiment of the present invention, the second piston is provided with a limiting hole, and the limiting portion is provided with a waist-shaped hole at the position corresponding to the limiting hole. The waist-shaped hole is arranged along the movement direction of the second piston, and a pin is arranged in the limiting hole and the waist-shaped hole.

[0009] As a further improvement of one embodiment of the present invention, it also includes a plug, which is arranged above the valve needle hanging platform. The valve needle hanging platform and the plug are threadedly connected to the second piston to adjust the position of the valve needle hanging platform and thus adjust the position of the valve needle, or remove the valve needle hanging platform and the plug from the second piston.

[0010] As a further improvement of one embodiment of the present invention, a polygonal groove is provided on the upper end of the valve needle hanging platform, and a polygonal through hole is provided through the plug at the position corresponding to the polygonal groove to facilitate the rotation of the valve needle hanging platform and the plug.

[0011] As a further improvement of an embodiment of the present invention, a friction plate is provided between the valve needle hanging platform and the plug to prevent the valve needle hanging platform from loosening.

[0012] As a further improvement of one embodiment of the present invention, the first piston divides the through hole into an upper chamber and a lower chamber, and the cylinder also includes a first oil circuit joint and a second oil circuit joint, which are respectively connected to the upper chamber and the lower chamber.

[0013] As a further improvement of an embodiment of the present invention, at least one sealing ring is provided between the first piston, the cylinder and the base.

[0014] Compared with the prior art, the technical effect of the present invention is that: the embodiment of the present invention divides the single piston in the prior art into a first piston and a second piston, the first piston drives the second piston to perform reciprocating motion, the second piston fixes the valve needle, and there is a floating gap between the first piston and the second piston. When the position of the hole through which the valve needle passes on the diverter plate is offset due to thermal expansion and contraction, due to the floating gap between the first piston and the second piston, the valve needle is subjected to the action of force, and the second piston produces radial displacement in the floating gap, thereby ensuring the linear setting of the valve needle, avoiding the phenomenon of valve needle bending or jamming, and contributing to the stability of the valve needle sealing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the structure of the oil cylinder in the embodiment of the present invention.

[0016] Figure 2 yes Figure 1 Front view of the cylinder shown in .

[0017] Figure 3 yes Figure 2 Schematic cross-sectional view along line AA.

[0018] Figure 4 yes Figure 2 Schematic cross-sectional view along line BB.

[0019] Figure 5 yes Figure 2 Schematic cross-sectional view along the CC line.

[0020] Figure 6 yes Figure 3 Enlarged view of point D in the middle.

[0021] Figure 7 yes Figure 3 The structural diagram of the support seat is shown in FIG.

[0022] 1. Cylinder; 11. Through hole; 111. Upper chamber; 112. Lower chamber; 12. First oil circuit connector; 13. Second oil circuit connector; 2. Base; 21. First clearance hole; 3. First piston; 31. First protrusion; 32. Sealing ring; 4. Second piston; 41. Limiting hole; 42. Second protrusion; 43. Retaining ring; 44. Retaining spring; 45. Annular groove; 5. Support seat; 51. Main body; 52. Second clearance hole; 53. Limiting part; 531. Waist-shaped hole; 532. Pin; 6. Valve needle hanging platform; 61. T-hole; 62. Polygonal groove; 7. Plug; 711. Polygonal through hole; 8. Valve needle; 9. Friction plate. DETAILED DESCRIPTION

[0023] The present invention will be described in detail below with reference to the various embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0024] As used herein, terms indicating spatial relative positions such as "upper," "above," "lower," and "below" are used for ease of explanation to describe the relationship of one unit or feature relative to another unit or feature as shown in the accompanying drawings. Terms of spatial relative position may be intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the drawings. For example, if the device in the drawings were turned over, units described as being "below" or "beneath" other units or features would be "above" the other units or features. Thus, the exemplary term "below" may encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein interpreted accordingly.

[0025] Furthermore, it should be understood that although the terms first, second, etc. may be used herein to describe various elements or structures, these described objects should not be limited by these terms. These terms are merely used to distinguish the described objects from each other. For example, a first piston may be referred to as a second piston, and similarly, a second piston may be referred to as a first piston without departing from the scope of protection of this application.

[0026] The first embodiment of the present invention provides an oil cylinder, which is used in a hot runner system and fixed on a manifold therein, such as Figure 1-3 As shown, it includes: a cylinder 1, which is penetrated by a through hole 11; a base 2, which is connected to the lower end of the cylinder 1 and is penetrated by a first give way hole 21, and the first give way hole 21 is connected to the through hole 11; a first piston 3, the first piston 3 is a hollow structure, is arranged in the through hole 11 and the first give way hole 21, and reciprocates along the axial direction of the through hole 11 and the first give way hole 21; a second piston 4, which is fixedly arranged in the first piston 3 along the axial direction to reciprocate along the aforementioned axial direction with the first piston 3, wherein the first piston 3 and the second piston 4 are provided with a floating gap in the radial direction perpendicular to the axis, so that the second piston 4 can move radially in a certain floating space under the action of external force, and a valve needle hanging platform 6 is provided in the second piston 4.

[0027] A valve needle 8 is fixedly connected under the valve needle hanging platform 6. When the hole through which the valve needle 8 passes is offset due to thermal expansion and contraction of the diverter plate, the valve needle 8 is acted upon by an external force, causing the second piston 4 to be displaced within the above-mentioned floating gap, thereby ensuring the linear setting of the valve needle 8, avoiding the bending or jamming of the valve needle 8, and contributing to the stability of the sealing process of the valve needle 8.

[0028] Specifically, the second piston 4 is hollow, and the valve needle mounting platform 6 is threadedly connected to the second piston 4. A T-shaped hole 61 is provided at the lower end of the valve needle mounting platform 6 for securing the valve needle 8 to the valve needle mounting platform 6. This threaded connection allows the position of the valve needle mounting platform 6, and thus the position of the valve needle 8, to be adjusted as needed, preventing the valve needle 8 from being too long or too short due to thermal expansion or machining errors, which could affect the sealing of the valve needle 8.

[0029] Furthermore, the oil cylinder also includes a plug 7, which is arranged above the valve needle hanging platform 6 and is also threadedly connected to the second piston 4. Preferably, a polygonal groove 62 is provided at the upper end of the valve needle hanging platform 6, and a polygonal through-hole 711 is provided through the plug 7 at the position corresponding to the polygonal groove 62. When the valve needle 8 of the hot runner system needs to be maintained or replaced, the valve needle hanging platform 6 and the plug 7 are rotated and removed from the second piston 4 using the polygonal groove 62 and the polygonal through-hole 711, and the valve needle 8 can be removed. There is no need to disassemble the cylinder barrel 1, base 2 and piston, thus avoiding hydraulic oil leakage. In this embodiment, the polygons in the polygonal groove 62 and the polygonal through-hole 711 are both hexagonal, so that they can be adjusted with a commonly used hexagonal wrench without the need for a specially customized wrench corresponding to the polygon.

[0030] Preferably, a friction plate 9 is provided between the valve needle hanging platform 6 and the plug 7 to prevent the valve needle hanging platform 6 from loosening during the reciprocating motion, thereby affecting the position of the valve needle 8 and thus affecting the sealant.

[0031] Further, such as Figure 3 and Figure 7 As shown, the oil cylinder further includes a support base 5, which includes a body 51, a second clearance hole 52 provided in the body 51, and a second stopper 53 extending upwardly from the second clearance hole 52 in the body 51. The stopper 53 extends from the lower end of the first piston 3 into the first piston 3. The second piston 4 is disposed within the stopper 53, and a clearance is provided between the second piston 4 and the stopper 53 in the aforementioned radial direction, allowing the second piston 4 to produce radial displacement within the stopper 53. The second piston 4 is provided with a limit hole 41. The stopper 53 has a waist-shaped hole 531 provided at the position corresponding to the limit hole 41. The waist-shaped hole 531 is arranged along the direction of movement of the second piston 4. A pin 532 is disposed within the limit hole 41 and the waist-shaped hole 531. The pin 532 slides within the waist-shaped hole 531, allowing the second piston 4 to reciprocate with the first piston 3 but not rotate, thereby preventing the valve needle 8 from rotating.

[0032] In this embodiment, the cylinder 1 and the base 2 are fixed in a template, the lower end of the support seat 5 is fixed to the diverter plate, the cylinder 1, the base and the support seat 5 are all in a fixed state, and the second piston 4 drives the plug 7, the valve needle hanging platform 6 and the valve needle 8 to make reciprocating motion under the reciprocating motion of the first piston 3, thereby realizing the sealing of the valve needle 8.

[0033] Further, such as Figure 3 and Figure 5 As shown, the first piston 3 has an inner wall with a first protrusion 31 disposed thereon, and the second piston 4 has an outer wall with a second protrusion 42 disposed thereon and a fixing structure. The fixing structure comprises a retaining ring 43, a retaining spring 44, and an annular groove 45 disposed on the exterior of the second piston 4. The first protrusion 31 is disposed on the second protrusion 42, the retaining ring 43 is disposed on the first protrusion 31, the annular groove 45 is positioned to mate with the retaining ring 43, and the retaining spring 44 is disposed within the annular groove 45 and abuts against the retaining ring 43. The first protrusion 31 is spaced apart from the outer wall of the second piston 4, while the second protrusion 42 and the fixing structure are spaced apart from the inner wall of the first piston 3. This arrangement positions the first protrusion 31 between the second protrusion 42 and the fixing structure, securing the first and second pistons 3 and 4 in the aforementioned axial direction. The reciprocating motion of the first piston 3 drives the movement of the second piston 4. Furthermore, the second piston 4 and the first piston 3 can undergo relative motion in the aforementioned radial direction.

[0034] Further, such as Figure 4-5 As shown, the first piston 3 divides the through hole 11 into an upper chamber 111 and a lower chamber 112. The cylinder barrel 1 also includes a first oil circuit connector 12 and a second oil circuit connector 13, which are connected to the upper chamber 111 and the lower chamber 112, respectively. At least one sealing ring 32 is provided between the first piston 3, the cylinder barrel 1, and the base 2. Preferably, the sealing ring 32 is provided between the cylinder barrel 1 and the first piston 3 above the upper chamber 111, and also between the base 2 and the first piston 3 below the lower chamber 112. This ensures that hydraulic oil does not leak from the gap between the cylinder barrel 1, the base 2, and the first piston 3, and also ensures that the first piston 3 can move normally.

[0035] It should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation method can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0036] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. An oil cylinder used in a hot runner system and fixed on a manifold therein, characterized in that: include: The cylinder is provided with a through hole; A base is connected to the lower end of the cylinder and is provided with a first clearance hole therethrough, wherein the first clearance hole is communicated with the through hole; a first piston disposed in the through hole and the first clearance hole and reciprocating along the axial direction of the through hole and the first clearance hole, wherein the first piston is a hollow structure; a second piston fixedly disposed in the first piston along the axial direction so as to reciprocate along the axial direction with the first piston, wherein a floating gap is provided between the first piston and the second piston in a radial direction perpendicular to the axial direction so that the second piston can move radially within a certain floating space under the action of an external force, and a valve needle hanging platform is provided in the second piston; The first piston is formed with an inner wall, and a first protrusion is provided on the inner wall; the second piston is formed with an outer wall, and a second protrusion and a fixing structure are provided on the outer wall; the first protrusion is cooperatively arranged between the second protrusion and the fixing structure; the first protrusion is spaced apart from the outer wall of the second piston; the second protrusion and the fixing structure are spaced apart from the inner wall of the first piston; The fixing structure comprises a retaining ring, a retaining spring and an annular groove provided on the outer wall of the second piston. The retaining ring is provided on the first protrusion. The setting position of the annular groove matches the retaining ring. The retaining spring is provided in the annular groove and abuts against the retaining ring. The oil cylinder also includes a support seat, the lower end of which is fixed to the diverter plate. The support seat includes a main body, a second clearance hole arranged on the main body, and a limiting portion extending upward along the second clearance hole on the main body. The limiting portion extends into the first piston from the lower end of the first piston, and the second piston is arranged in the limiting portion, and a floating gap is provided between the second piston and the limiting portion in the aforementioned radial direction.

2. The oil cylinder according to claim 1, characterized in that: The second piston is provided with a limiting hole, and the limiting portion is provided with a waist-shaped hole at a position corresponding to the limiting hole. The waist-shaped hole is arranged along the movement direction of the second piston, and a pin is arranged in the limiting hole and the waist-shaped hole.

3. The oil cylinder according to claim 1, characterized in that: It also includes a plug, which is arranged above the valve needle hanging platform. The valve needle hanging platform and the plug are all threadedly connected to the second piston to adjust the position of the valve needle hanging platform to adjust the position of the valve needle, or to remove the valve needle hanging platform and the plug from the second piston.

4. The oil cylinder according to claim 3, characterized in that: A polygonal groove is provided at the upper end of the valve needle hanging platform, and a polygonal through hole is provided through the plug at a position corresponding to the polygonal groove to facilitate the rotation of the valve needle hanging platform and the plug.

5. The oil cylinder according to claim 3, characterized in that: A friction plate is provided between the valve needle hanging platform and the plug to prevent the valve needle hanging platform from loosening.

6. The oil cylinder according to claim 1, characterized in that The first piston divides the through hole into an upper chamber and a lower chamber. The cylinder further includes a first oil circuit joint and a second oil circuit joint. The first oil circuit joint and the second oil circuit joint are respectively connected to the upper chamber and the lower chamber.

7. The oil cylinder according to claim 1, characterized in that: At least one sealing ring is provided between the first piston, the cylinder and the base.

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