Check valve unit

Abstract

To provide a check valve unit which can reliably fix a seat relief to an attachment part of a plunger hole with a simple structure, can be easily manufactured without increasing the number of components, and can suppress deformation of a plunger.SOLUTION: A check valve unit 100 includes a seat relief 120 and a cap member 110. A plunger P has an outside relief hole Ps for providing communication between the inside and the outside of the plunger P at an attachment part Pd. The cap member 110 has a cap ceiling surface 111, an oil leak part 113 penetrating the cap ceiling surface 111, and a skirt wall 112. The skirt wall 112 has outer contact protrusive surfaces 112a and inner contact protrusive surfaces 112b. A radius of a circumscription circle Ca on a plurality of outer contact protrusive faces 112a is larger than an inner diameter of the attachment part Pd, and a radius of an inscription circle Cb on a plurality of inner contact protrusive surfaces 112b are smaller than an outside diameter of a fit part 121.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a check valve unit incorporated in a plunger of a high-pressure relief valve of a tensioner.

Background Art

[0002] Conventionally, as a tensioner incorporating a check valve unit in a plunger, the tensioner described in Citation Document 1 is known. The tensioner described in this Patent Document 1 inserts a check valve unit (relief valve unit 151) into the inner mounting portion in the plunger hole 122. The check valve unit (relief valve unit 151) includes a seat relief (seat member 152) containing a check valve (valve ball 153, spring 160, stopper member 155), and a cap member 156 covering a fitting portion (engagement recess 174) provided on the insertion direction side of the seat relief (seat member 152) into the plunger hole 122. In the check valve unit (relief valve unit 151) of this tensioner, the outermost diameter of the side surface of the seat relief (seat member 152) is formed to be substantially the same as the inner diameter of the plunger hole 122, and the seat relief (seat member 152) is fixed to the mounting portion by being press-fitted into the plunger hole 122.

[0003] Also, as a tensioner incorporating a check valve unit in a plunger, the tensioner described in Citation Document 2 is known. The tensioner described in this Patent Document 2 inserts a check valve unit (relief valve unit 151) into the inner mounting portion in the plunger hole 122. The check valve unit (relief valve unit 151) includes a seat relief (seat member 152) containing a check valve, and a cap member 156 covering a fitting portion provided on the insertion direction side of the seat relief (seat member 152) into the plunger hole 122. This tensioner further includes a resin fixing member 180 for fixing the check valve unit (relief valve unit 151) to the mounting part. This eliminates the need to precisely machine the outermost diameter of the seat relief (seat member 152) and the inner diameter of the plunger hole 122 to the press-fit dimensions of the seat relief (seat member 152), thereby reducing processing costs. Furthermore, since the fixing member 180 is made of resin, even if the fixing member 180 is pressed into the plunger hole 122, the plunger 120 will not deform, and the shape accuracy of the plunger 120 can be ensured. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-113178 [Patent Document 2] Japanese Patent Publication No. 2019-157974 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, the tensioner check valve unit known from the above patent document still had room for improvement.

[0006] In other words, the tensioner check valve unit known in Patent Document 1 is fixed to the mounting part by press-fitting the seat relief into the plunger hole, which requires precise machining of the outer diameter of the seat relief and the inner diameter of the plunger hole, potentially increasing machining costs. Furthermore, pressing the sheet relief into the plunger hole could deform the plunger, potentially increasing processing costs due to additional machining required to ensure the plunger's shape accuracy. Furthermore, the tensioner check valve unit known in Patent Document 2 requires the addition of separate fixing members to secure the seat relief and cap members, which could lead to increased manufacturing costs due to the increased number of parts. Furthermore, since the fixing member is made of resin, utmost care had to be taken when pressing it into the plunger hole, as there was a possibility that the fixing member might be scraped.

[0007] The present invention aims to solve these problems and provide a check valve unit that has a simple structure, can securely fix the seat relief to the mounting portion of the plunger hole, facilitates manufacturing without increasing the number of parts, and suppresses deformation of the plunger. [Means for solving the problem]

[0008] The check valve unit of the present invention is a check valve unit built into the plunger of a high-pressure relief valve of a tensioner, the check valve unit having a seat relief that encloses the check valve and is inserted into a plunger hole provided in the plunger, and a cap member that covers a fitted portion provided on the side of the seat relief in the direction of insertion into the plunger hole, the plunger has an external relief hole that communicates the inside and outside of the plunger at the mounting portion of the plunger hole, and the cap member has a flat cap top surface and the cap The problem is solved by having a hole-shaped oil leak portion that penetrates the top surface and a skirt wall that hangs down from the top surface of the cap, the skirt wall having a plurality of outward contact convex surfaces that project radially outward and a plurality of inward contact convex surfaces that project radially inward, the radius of the circumscribed circles of the plurality of outward contact convex surfaces before the check valve unit is built into the plunger is greater than the inner diameter of the mounting portion of the plunger hole, and the radius of the inscribed circles of the plurality of inward contact convex surfaces before the cap member is placed over the fitting portion is smaller than the outer diameter of the fitting portion. [Effects of the Invention]

[0009] According to the check valve unit of claim 1, the skirt wall of the cap member has a plurality of outward-projecting contact convex surfaces and a plurality of inward-projecting contact convex surfaces. Before the check valve unit is built into the plunger, the radius of the circumscribed circles of the plurality of outward-projecting convex surfaces is greater than the inner diameter of the mounting portion of the plunger hole. Before the cap member is placed over the mating portion, the radius of the inscribed circles of the plurality of inward-projecting convex surfaces is smaller than the outer diameter of the mating portion. Therefore, by inserting the check valve unit to the back of the mounting portion of the plunger hole while it is placed over the mating portion, the top surface of the cap comes into close contact with the back surface of the plunger hole, closing the space between the top surface of the cap and the back surface of the plunger hole. The skirt wall flexibly and elastically deforms, bringing the mounting portion and the outward-projecting convex surfaces into close contact. The repulsive force associated with the elastic deformation of the skirt wall also brings the mating portion and the inward-projecting convex surfaces into close contact, allowing the check valve unit to be firmly fastened to the mounting portion. This eliminates the need to precisely design and machine the outer diameter of the seat relief to fit into the plunger hole, simplifying manufacturing and reducing production costs.

[0010] According to the configuration described in claim 2, the skirt wall further has a plurality of intermediate convex surfaces projecting radially outward, and the radius of the circumscribed circle of the plurality of intermediate convex surfaces is smaller than the radius of the plurality of outward contact convex surfaces. Therefore, the repulsive force due to the elastic deformation of the skirt wall when the check valve unit is inserted into the mounting portion can be made even stronger, and the check valve unit can be fastened to the mounting portion even more firmly. According to the configuration described in claim 3, since the cap member is made of a metal material, it is less prone to deterioration than one made of a resin material, and the fastening force to the mounting portion of the check valve unit can be maintained for a long period of time.

[0011] According to the configuration described in claim 4, the outermost diameter of the seat relief is formed to be smaller than the inner diameter of the plunger hole. Therefore, when fixing the check valve unit to the mounting part, contact between the plunger hole and the seat relief can be minimized, and deformation of the plunger can be suppressed. Furthermore, the amount of oil leaked when the check valve is closed can be adjusted by adjusting the clearance between the seat relief and the plunger hole. According to the configuration described in claim 5, the check valve has a valve ball and a relief spring that biases the valve ball, and the cap member has a rod-shaped stopper hanging down from the top surface of the cap, and the stopper is configured to be insertable into the relief spring, so that the relief spring through which the stopper is inserted can suppress displacement of its central axis and can reliably press the valve ball from the correct position in the correct direction.

[0012] According to the configuration described in claim 6, a cap communication groove is formed on the top surface of the cap, which communicates from the outer circumference of the top surface of the cap to the oil leak portion. As a result, an oil leak passage is formed between the top surface of the cap and the back surface of the plunger hole, with the cap communication groove acting as a flow path. By adjusting the number and size of the cap communication grooves, the amount of oil leaked when the check valve is closed can be adjusted. According to the configuration described in claim 7, a seat relief communication groove is formed on the contact end face, which communicates from the outer circumference of the contact end face to the oil leak portion on the cap top surface that is in contact with the seat relief. As a result, an oil leak passage can be formed between the cap top surface and the contact end face, with the seat relief communication groove acting as a flow path. By adjusting the number and size of the seat relief communication grooves, the amount of oil leaked when the check valve is closed can be adjusted. [Brief explanation of the drawing]

[0013] [Figure 1] A front cross-sectional view of a plunger P fitted with a check valve unit 100 according to one embodiment of the present invention. [Figure 2] An enlarged front cross-sectional view of a plunger P fitted with a check valve unit 100 according to one embodiment of the present invention. [Figure 3] A cross-sectional view A-A' of a plunger P fitted with a check valve unit 100 according to one embodiment of the present invention. [Figure 4] A perspective view of the cap member 110 of a check valve unit 100 according to one embodiment of the present invention. [Figure 5] Top view of the cap member 110 of the check valve unit 100 according to an embodiment of the present invention. [Figure 6] Bottom view of the cap member 110 of the check valve unit 100 according to an embodiment of the present invention. [Figure 7] Perspective view of the seat relief 120 of the check valve unit 100 according to an embodiment of the present invention. [Figure 8] Perspective view of the stopper 130 of the check valve unit 100 according to an embodiment of the present invention. [Figure 9] Front cross-sectional view of the plunger P to which the check valve unit 100 according to an embodiment of the present invention can be attached. [Figure 10] Perspective view showing the cap member 210 of the check valve unit according to an embodiment of the present invention. [Figure 11] Perspective view showing the seat relief 220 of the check valve unit according to an embodiment of the present invention. [Figure 12] Perspective view showing the cap member 310 of the check valve unit according to an embodiment of the present invention. [Figure 13] Front cross-sectional view of the plunger P with the check valve unit according to an embodiment of the present invention attached. <� [Figure 14] Cross-sectional view taken along line B-B' of the plunger P with the check valve unit according to an embodiment of the present invention attached.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, the check valve unit 100 according to an embodiment of the present invention will be described based on the drawings. As shown in Figures 1 to 3, the check valve unit 100 is built into the plunger P of the tensioner's high-pressure relief valve and includes a seat relief 120 that encloses the spring S and valve ball B constituting the check valve and is inserted into a plunger hole Ph provided in the plunger P, a cap member 110 that covers the fitted portion 121 provided on the side of the seat relief 120 that is inserted into the plunger hole Ph, and a stopper 130 that prevents the spring S from shifting position. Furthermore, at least the cap member 110 and the seat relief 120 are made of metal material.

[0015] As shown in Figures 4 to 6, the cap member 110 has a flat cap top surface 111, a hole-shaped oil leak portion 113 that penetrates the cap top surface 111, and a skirt wall 112 that hangs down from the cap top surface 111 via a tapered surface 111a. The skirt wall 112 is formed in a wave shape, having three outward-projectingcircle-circles Cc with circumscribed circles Cc having a radius smaller than that of the outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-projecting outward-circle-circles Cc having a radius smaller than that of the outward-projecting outward-projecting outward-project Furthermore, the radius of the circumscribed circle Ca of the outward contact convex surface 112a is greater than the radius of the inner circumferential surface of the mounting portion Pd of the plunger P and smaller than the radius of the inner circumferential surface of the plunger hole Ph, and the radius of the inscribed circle Cb of the inward contact convex surface 112b is smaller than the radius of the outer circumferential surface of the fitted portion 121 of the seat relief 120.

[0016] As shown in Figures 2 and 7, the seat relief 120 has a fitted portion 121, a ring-shaped flange portion 122 that protrudes radially outward from the lower part of the fitted portion 121, and a valve housing portion 123 formed below the flange portion. The upper part of the fitted portion 121 is perforated through to the valve housing portion 123, with a communication hole 124 at the end on the valve housing portion 123 side and a mounting hole 125 at the end on the fitted portion 121 side. Furthermore, the radius of the outer circumferential surface of the flange portion 122 is smaller than the radius of the inner circumferential surface of the mounting hole 125 of the plunger P, the radius of the inner circumferential surface of the communication hole 124 is smaller than the radius of the valve ball B, and the radius of the inner circumferential surface of the mounting hole 125 is larger than the radius of the valve ball B.

[0017] As shown in Figures 2 and 8, the stopper 130 has a rod-shaped insertion projection 131, a wall-shaped mounting wall portion 132 formed on the upper part of the insertion projection 131, and an oil passage portion 133 that penetrates the mounting wall portion 132. Furthermore, the radius of the outer circumferential surface of the mounting wall portion 132 is formed to be less than or equal to the radius of the inner circumferential surface of the mounting hole 125.

[0018] As shown in Figures 1, 2, and 9, the plunger P has a plunger hole Ph that opens the lower side of the plunger P, a mounting portion Pd that connects to the upper part of the plunger hole Ph, and an external relief hole Ps that connects to the upper part of the mounting portion Pd and opens the upper side of the plunger P. Furthermore, the radius of the inner surface of the mounting portion Pd is smaller than the radius of the inner surface of the plunger hole Ph, and larger than the radius of the inner surface of the outer relief hole Ps.

[0019] Next, the procedure for attaching the check valve unit 100 according to one embodiment of the present invention to the plunger P will be explained with reference to Figures 1 to 3. First, insert valve ball B through mounting hole 125 of seat relief 120, and then insert spring S. In this case, since the radius of valve ball B is larger than the radius of the inner surface of the communication hole 124, the valve ball fits inside the seat relief 120 so as to block the communication hole 124.

[0020] Furthermore, the stopper 130 is inserted so that the insertion projection 131 enters the inside of the spring S. In this case, since the radius of the outer surface of the mounting wall portion 132 is less than or equal to the radius of the inner surface of the mounting hole 125, the stopper 130 that has entered the seat relief can be prevented from shifting position by the mounting hole 125, and the shifting position of the spring S into which the insertion projection 131 has entered can also be suppressed. This allows the positional relationship between the valve ball B and the spring S to be maintained at the correct level.

[0021] Furthermore, the cap member 110 is placed over the fitting portion 121 so that the upper surface of the fitting portion 121 is in close contact with the lower surface of the cap top surface 111. At this time, the radius of the inscribed circle Cb of the six inward contact convex surfaces 112b is smaller than the radius of the outer surface of the fitted portion 121, but because the skirt wall 112 is formed in a wave shape, it expands in diameter while elastically deforming and fits over the fitted portion 121.

[0022] The check valve unit 100 assembled as described above is inserted through the opening of the plunger hole Ph of the plunger P. At this time, since the radii of the circumscribed circles Ca of the three outward contact convex surfaces 112a and the radius of the outer surface of the flange portion 122 are smaller than the radius of the inner surface of the plunger hole Ph, the check valve unit 100 does not particularly interfere with the plunger hole Ph and can move to the mounting portion Pd. Furthermore, since the radii of the circumscribed circles Ca of the three outward contact convex surfaces 112a are greater than the radius of the inner circumferential surface of the mounting portion Pd, and the radius of the outer circumferential surface of the flange portion 122 is smaller than the radius of the inner circumferential surface of the mounting portion Pd, the seat relief 120 does not directly contact the mounting portion Pd, and the cap member 110 enters the mounting portion Pd while elastically deforming the corrugated skirt wall 112.

[0023] The check valve unit 100 is inserted into the mounting portion Pd until the top surface of the cap 111 is in close contact with the back of the mounting portion Pd. As a result, the oil leak portion 113 of the check valve unit 100 and the external relief hole of the plunger P are connected, and the space between the mounting portion Pd and the top surface of the cap 111 is closed, so that the oil inside the plunger P can only pass through when the valve ball B has disengaged from the communication hole 124.

[0024] Furthermore, because the outer contact convex surface 112a of the skirt wall 112 is elastically deformed by the mounting portion Pd, and the inner contact convex surface 112b is elastically deformed by the fitted portion 121, the repulsive force of the skirt wall 112 becomes stronger, and the check valve unit 100 can be firmly fastened to the mounting portion Pd. This eliminates the need to press-fit the check valve unit 100, suppresses deformation of the plunger P to which the check valve unit 100 is attached, and eliminates the need to machine the cap member 110 and seat relief 120 with high precision. In other words, it is possible to suppress cost increases when manufacturing the cap member 110 and the seat relief 120. Furthermore, since the cap member 110 and the seat relief 120 are made of metal material, they are less prone to deterioration compared to resin material, and in particular, the resilience of the cap member 110 can be maintained firmly and for a long period of time. Furthermore, there is no risk of the cap member 110 and seat relief 120, which are made of metal, being worn down when inserted into the plunger hole Ph.

[0025] Furthermore, since the skirt wall 112 has an intermediate convex surface 112c, the repulsive force due to the elastic deformation of the skirt wall 112 when the check valve unit 100 is inserted into the mounting portion Pd can be made even stronger, and the check valve unit 100 can be fastened even more securely to the mounting portion Pd.

[0026] The forms of the cap member 110, seat relief 120, and stopper 130 are not limited to these. For example, as shown in Figure 10, a cap communication groove 214 is provided on the upper surface of the cap top surface 211 of a cap member 210 having the same shape as the cap member 110. This groove communicates from the oil leak portion 213 to the skirt wall 212, so that when the check valve unit 100 is inserted into the mounting portion Pd, the cap communication groove 214 becomes an oil leak passage even if the mounting portion Pd and the cap top surface 211 are in close contact. This allows for easy adjustment of the amount of oil leaked when the check valve is closed by adjusting the size and number of the cap communication grooves 214.

[0027] Furthermore, as shown in Figure 11, for example, by providing a sheet relief communication groove 226 on the upper surface of the fitted portion 221 of the sheet relief 220, which has the same shape as the sheet relief 120, and connecting the mounting hole 225 with the outer peripheral surface of the fitted portion 221, the sheet relief communication groove 226 becomes an oil leak passage even when the lower surface of the cap top surface 111 of the cap member 110 and the upper surface of the fitted portion 221 of the sheet relief 120 are in close contact. This allows for easy adjustment of the amount of oil leaked when the check valve is closed by adjusting the size and number of the seat relief communication grooves 226.

[0028] Furthermore, as shown in Figures 12 to 14, for example, by providing a mounting wall portion 316 extending downward from the periphery of the oil leak portion 313, an oil passage portion 315 penetrating the mounting wall portion 316, and an insertion projection 317 extending downward from the lower end of the mounting wall portion 316 on the top surface 311 of the cap member 310 which has the same shape as the cap member 110, the displacement of the spring S can be prevented without using the stopper 130. Furthermore, the reduction in the number of parts makes manufacturing even easier.

[0029] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design modifications can be made without departing from the present invention as described in the claims.

[0030] In the embodiments described above, the spring was explained as being inserted into the insertion projection, but the arrangement of the spring is not limited to this. For example, without providing an insertion projection, misalignment may be prevented by bringing the inner circumferential surface of the seat relief closer to the outer diameter of the spring. Furthermore, in the embodiments described above, the skirt wall was described as having three outward-contacting convex surfaces, six inward-contacting convex surfaces, and three intermediate convex surfaces. However, the configuration of the skirt wall is not limited to this. For example, there may be no intermediate convex surfaces, and there may be four or more outward-contacting convex surfaces and four or more inward-contacting convex surfaces.

[0031] Furthermore, although the above-described embodiment was explained in which a cap communication groove is provided on the upper surface of the cap top, the arrangement of the cap communication groove is not limited to this, and for example, it may be provided on the lower surface of the cap top. Furthermore, in the embodiments described above, the oil leak passage was provided by forming a cap communication groove or a seat relief communication groove on the top surface of the cap or the upper surface of the fitted portion. However, the arrangement and formation method of the oil leak passage are not limited to this, and for example, it may be formed in the form of a hole that penetrates the fitted portion.

[0032] Furthermore, although the above-described embodiment was explained assuming that an oil leak section is provided in the center of the top surface of the cap, the number and arrangement of oil leak sections are not limited to this, and for example, multiple oil leak sections may be provided on the top surface of the cap. Furthermore, although the above-described embodiment was explained assuming that a tapered surface is provided between the top surface of the cap and the skirt wall, the configuration of the cap member is not limited to this, and for example, a tapered surface may not be provided. [Explanation of Symbols]

[0033] 100... Check valve unit 110, 210, 310... Cap components 111, 211, 311... Top of cap 111a, 211a, 311a... Tapered surface 112, 212, 312... Skirt wall 112a, 212a, 312a... Outer contact convex surface 112b, 212b, 312b... Inner contact convex surface 112c, 212c, 312c... Intermediate convex surface 113, 213, 313... Oil leak section 214... Cap connecting groove 120 ··· Seat relief 121, 221 ··· Fitting part 122, 222... Flange section 123, 223... Valve housing 124...Communication hole 125, 225... Mounting holes 226... Seat relief connecting groove 130 ··· Stopper 131, 317 ··· Insertion projection 132, 316 ··· Mounting wall section 133, 315... Oil passage section Ca ··· Circumscribed circle of an outward-contacting convex surface Cb ··· Inscribed circle of an inwardly contacting convex surface Cc ··· Circumscribed circle of the intermediate convex surface S ··· Spring B... Valve ball P... Plunger Pd ··· Mounting part Ph ··· plunger hole Ps ··· External relief holes

Claims

1. A check valve unit built into the plunger of a tensioner's high-pressure relief valve, The check valve unit comprises a seat relief that encloses the check valve and is inserted into a plunger hole provided in the plunger, and a cap member that covers a fitted portion of the seat relief provided on the side of the seat relief that is inserted into the plunger hole. The plunger has an external relief hole in the mounting portion of the plunger hole that connects the inside and outside of the plunger, The cap member has a flat cap top surface, a hole-shaped oil leak portion penetrating the cap top surface, and a skirt wall hanging down from the cap top surface. The skirt wall has a plurality of outward contact convex surfaces projecting radially outward and a plurality of inward contact convex surfaces projecting radially inward. Before the check valve unit is incorporated into the plunger, the radius of the circumscribed circle of the plurality of outward contact convex surfaces is greater than the inner diameter of the mounting portion of the plunger hole. A check valve unit characterized in that, before the cap member is placed over the fitting portion, the radius of the inscribed circle of the plurality of inward contact convex surfaces is smaller than the outer diameter of the fitting portion.

2. The outer contact convex surface and the inner contact convex surface are smoothly connected. The aforementioned skirt wall further has a plurality of intermediate convex surfaces projecting radially outward, The check valve unit according to claim 1, characterized in that the radius of the circumscribed circle of the plurality of intermediate convex surfaces is smaller than the radius of the circumscribed circle of the plurality of outward contact convex surfaces.

3. The check valve unit according to claim 1, characterized in that the cap member is made of a metal material.

4. The check valve unit according to claim 1, characterized in that the outermost diameter of the seat relief is formed to be smaller than the inner diameter of the mounting portion of the plunger hole.

5. The check valve has a valve ball and a relief spring that biases the valve ball. The cap member has a rod-shaped stopper that hangs down from the top surface of the cap, The check valve unit according to claim 1, characterized in that the stopper is configured to be insertable into the relief spring.

6. The check valve unit according to claim 1, characterized in that a cap communication groove is formed on the top surface of the cap, which communicates from the outer circumference of the top surface of the cap to the oil leak portion.

7. The check valve unit according to claim 1, characterized in that a seat relief communication groove is formed on the contact end face of the seat relief, which is the end face that is in close contact with the top surface of the cap, and the groove communicates from the outer circumference of the contact end face to the oil leak portion of the top surface of the cap that is in close contact with the seat relief.

8. A cap member for a check valve unit built into the plunger of a high-pressure relief valve of a tensioner, The cap member has a flat cap top surface, a hole-shaped oil leak portion penetrating the cap top surface, and a skirt wall hanging down from the cap top surface. The skirt wall has a plurality of outward contact convex surfaces projecting radially outward, a plurality of inward contact convex surfaces projecting radially inward, and a plurality of connecting surfaces that smoothly connect the outward contact convex surfaces and the inward contact convex surfaces. The radius of the circumscribed circle of the plurality of outward contact convex surfaces is greater than the inner diameter of the plunger hole provided in the plunger. A cap member for a check valve unit, characterized in that the radius of the inscribed circle of the plurality of inward contact convex surfaces is smaller than the outer diameter of the check valve unit.

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