Element-replaceable oil filter
The oil filter design with spirally arranged threads and a key portion simplifies cap attachment and detachment, addressing the complexity of conventional designs by reducing the rotation angle and ensuring secure attachment.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TOYOTA BOSHOKU KK
- Filing Date
- 2024-12-19
- Publication Date
- 2026-07-01
AI Technical Summary
Conventional oil filters require a large rotation angle for attaching and detaching the cap due to long female and male threads, making the process complicated.
The oil filter design includes spirally arranged female and male threads on the case and cap, with a key portion on the male thread to engage with the adjacent female thread, and a restricting projection to prevent backward movement, allowing for a shorter thread length and reduced rotation angle.
This configuration simplifies the attachment and detachment of the cap by reducing the required rotation angle, while maintaining sufficient contact area and pressure resistance, and prevents loosening during operation.
Smart Images
Figure 2026109187000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an element replacement type oil filter.
Background Art
[0002] Patent Document 1 discloses an element replacement type oil filter (hereinafter referred to as an oil filter). The oil filter disclosed in Patent Document 1 includes a housing having a case and a cap, and an element. The case is a one-sided bottomed cylindrical shape and is configured to be detachable from an internal combustion engine. An inlet through which the oil of the internal combustion engine flows in and an outlet through which the oil flows out are provided on the bottom wall of the case. The cap is a one-sided bottomed cylindrical shape and is configured to be detachable from the case. The element is housed inside the housing and filters the oil of the internal combustion engine.
[0003] A female screw thread is formed on the inner peripheral surface of the case. A male screw thread is formed on the outer peripheral surface of the cap. Also, an annular sealing member for sealing between the outer peripheral surface of the cap and the inner peripheral surface of the case is attached. The cap is attached to the case by screwing the cap into the case.
[0004] In the operation of replacing the element in such an oil filter, after removing the cap from the case, the element and the sealing member are removed from the cap. Subsequently, after attaching a new element and the sealing member to the cap, the cap is attached to the case.
Prior Art Documents
Patent Documents
[0005]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0006] In the oil filter disclosed in Patent Document 1, the cap is attached to the case by the frictional force acting between the female threads of the case and the male threads of the cap. In such conventional oil filters, the overall length of the female and male threads tends to be long in order to ensure sufficient frictional force, meaning that the rotation angle required to attach and detach the cap to the case tends to be large. This leads to the problem that the process of attaching and detaching the cap to the case becomes complicated. [Means for solving the problem]
[0007] An element-replaceable oil filter for solving the above problems comprises a housing that includes a cylindrical case with a closed bottom on one side having an inlet for oil from the internal combustion engine and an outlet for oil from the internal combustion engine, and a cylindrical cap with a closed bottom on one side that is detachably configured to be attached to the case, and an element housed inside the housing for filtering the oil, The inner circumferential surface of the case is provided with a plurality of female threads that extend spirally around the central axis of the case and are parallel to each other. The outer circumferential surface of the cap is provided with male threads that extend spirally around the central axis of the cap and engage with the female threads. When the forward direction of screwing the cap into the case is defined as the forward direction, The front end of the male thread is provided with a key portion that protrudes in the width direction of the male thread and is configured to engage with the front end of the adjacent projection in the axial direction of the male thread and the cap.
[0008] In this configuration, when the cap is screwed onto the case, a key portion provided at the front end of the male thread engages with the front end of the female thread adjacent to the male thread in the axial direction. This prevents the male thread from moving backward, i.e., prevents the screwed-on state of the cap from loosening. As a result, the overall length of the male and female threads can be shortened compared to a design without a key portion, i.e., the rotation angle required to attach and detach the cap from the case can be reduced. Therefore, attaching and detaching the cap from the case can be made easier. [Brief explanation of the drawing]
[0009] [Figure 1] Figure 1 is an exploded cross-sectional view of an oil filter according to one embodiment. [Figure 2] Figure 2 is a cross-sectional view of an oil filter according to one embodiment. [Figure 3] Figure 3 is a side view of a cap according to one embodiment. [Figure 4] Figure 4 is an unfolded view of the inner circumferential surface of a case according to one embodiment. [Figure 5] Figure 5 is an unfolded view of the outer surface of a cap according to one embodiment. [Figure 6] Figure 6 is a diagram showing the unfolded view of the inner surface of the case in Figure 4 and the unfolded view of the outer surface of the cap in Figure 5 superimposed on each other. [Modes for carrying out the invention]
[0010] An embodiment of an element-replaceable oil filter (hereinafter referred to as "oil filter") will be described below with reference to Figures 1 to 6. As shown in Figures 1 and 2, the oil filter comprises a housing 10 including a case 20 and a cap 40, an element 50, and a sealing member 60.
[0011] The case 20 is cylindrical with a bottom on one side and is configured to be detachable from the internal combustion engine. The case 20 has an inlet 24 through which oil from the internal combustion engine flows in and an outlet 25 through which the oil flows out.
[0012] The case 20 has a bottom wall 21 and a peripheral wall 22 extending upward from the periphery of the bottom wall 21. The case 20 has an opening 23 formed at the upper edge of the peripheral wall 22. The bottom wall 21 has a plurality of inflow ports 24 and outflow ports 25. At the central portion of the upper surface of the bottom wall 21, a support protrusion 26 protruding upward is provided. The plurality of inflow ports 24 are provided at intervals in the circumferential direction of the case 20 so as to surround the support protrusion 26. The outflow port 25 is provided at the central portion of the bottom wall 21 and penetrates the support protrusion 26 vertically. The outflow port 25 has an internal thread. By screwing a center bolt (not shown in the figure) constituting the oil path of the internal combustion engine into the outflow port 25, the case 20 is detachably attached to the internal combustion engine.
[0013] The case 20 is made of, for example, a hard resin. Note that the case 20 may be made of metal. On the inner peripheral surface of the case 20, a plurality of internal thread ridges 27 extending spirally about the central axis C of the case 20 and parallel to each other are provided.
[0014] The cap 40 is of a one-sided bottomed cylindrical shape and is configured to be detachable from the case 20. The cap 40 has a bottom wall 41 and a peripheral wall 42 extending downward from the periphery of the bottom wall 41. The cap 40 has an opening 43 formed at the lower edge of the peripheral wall 42.
[0015] On the outer peripheral surface of the cap 40, an external thread ridge 45 extending spirally about the central axis C of the cap 40 and engaging with the internal thread ridge 27 is provided. On the outer peripheral surface of the cap 40, a support groove 44 for supporting an annular seal member 60 is provided over the entire circumference. The support groove 44 is provided on the side of the bottom wall 41, that is, on the upper side, rather than the portion where the external thread ridge 45 is provided on the outer peripheral surface of the cap 40.
[0016] The cap 40 is made of, for example, a hard resin. Note that the cap 40 may be made of metal. Element 50 is housed inside the housing 10 and filters oil. Element 50 is substantially cylindrical, called a so-called chrysanthemum type, and is supported by the upper surface of the support protrusion 26.
[0017] <The female thread 27 of the case 20 and the male thread 45 of the cap 40> Hereinafter, the front and rear of the screwing direction S of the cap 40 with respect to the case 20 are simply referred to as the front and rear, respectively, and the width direction of the male thread 45, that is, the direction orthogonal to both the screwing direction S and the protruding direction of the male thread 45 is simply referred to as the width direction for explanation.
[0018] As shown in FIGS. 4 to 6, a plurality of female threads 27 are provided side by side at intervals in the circumferential direction of the case 20. A plurality of male threads 45 are provided side by side at intervals in the circumferential direction of the cap 40. In FIG. 6, the configuration of the cap 40 is shown by a two-dot chain line.
[0019] In the present embodiment, four female threads 27 and four male threads 45 are provided respectively. The male thread 45 and the female thread 27 of the present embodiment are sawtooth threads. As shown in FIGS. 3, 5, and 6, a key portion 47 is provided at the front end of the male thread 45 so as to protrude in the width direction and be engageable with the front end 28 of the female thread 27 adjacent to the male thread 45 in the axial direction of the cap 40.
[0020] The key portion 47 is provided only on one of the four male threads 45. As shown in FIG. 3, the key portion 47 has a front inclined surface 48 that inclines so that the protruding height in the width direction becomes smaller toward the front side. The key portion 47 is located on the rear side of the front inclined surface 48 and has a rear inclined surface 49 that inclines so that the protruding height in the width direction becomes larger toward the front side. The inclination angle of the rear inclined surface 49 is larger than the inclination angle of the front inclined surface 48. The inclination angle here is the angle formed by a virtual line extending along the screwing direction S and the front inclined surface 48 or the rear inclined surface 49.
[0021] As shown in Figure 4, the front end 28 of the female thread 27 has an end face that is aligned with the width direction. The rear end 29 of the female thread 27 is tapered, with the width dimension gradually decreasing towards the rear, as it approaches the center in the width direction.
[0022] As shown in Figure 5, the front end of the male thread 45 that does not have a key portion 47 is tapered, with the width gradually decreasing towards the front as it approaches the center in the width direction. The rear end of the male thread 45 is tapered, with the width gradually decreasing towards the rear as it approaches the center in the width direction.
[0023] As shown in Figure 6, a restricting projection 31 is provided in front of the female thread 27 on the inner circumferential surface of the case 20, which restricts the forward movement of the cap 40 relative to the case 20 by abutting against the front end of the male thread 45. The restricting projection 31 has a restricting surface 32 configured to allow contact with the male thread 45. The restricting surface 32 extends along the width direction of the female thread 27. In this embodiment, four restricting projections 31 are provided corresponding to four male threads 45.
[0024] <Operation of this embodiment> As shown in Figure 6, when the cap 40 is screwed onto the case 20, the key portion 47 provided at the front end of the male thread 45 engages with the front end 28 of the female thread 27 adjacent to the male thread 45 in the axial direction of the cap 40. This prevents the male thread 45 from moving backward, i.e., prevents the screwed-on state of the cap 40 on the case 20 from loosening. As a result, the overall length of the male thread 45 and the female thread 27 can be shortened compared to a case without the key portion 47, i.e., the rotation angle required to attach and detach the cap 40 to the case 20 can be reduced. Therefore, the cap 40 can be easily attached to and detached from the case 20.
[0025] <Effects of this embodiment> (1) The front end of the male thread 45 is provided with a key portion 47 that protrudes in the width direction of the male thread 45 and is configured to engage with the front end 28 of an adjacent female thread 27 in the axial direction of the male thread 45 and the cap 40.
[0026] With this configuration, the effects of the above embodiment are achieved, making it easy to attach and detach the cap 40 to the case 20. (2) On the inner circumferential surface of the case 20, a restricting projection 31 is provided in front of the female thread 27, which abuts against the front end of the male thread 45 to restrict the forward movement of the cap 40 relative to the case 20.
[0027] With this configuration, when the cap 40 is screwed onto the case 20, the front end of the male thread 45 on the outer surface of the cap 40 comes into contact with the restricting projection 31 on the inner surface of the case 20, thereby restricting the forward movement of the cap 40 relative to the case 20. This prevents the cap 40 from being screwed onto the case 20 too far. It also helps to alert the worker when the cap 40 has been fully screwed on.
[0028] (3) The male thread 45 and the female thread 27 are sawtooth threads. With this configuration, since the male thread 45 and the female thread 27 are sawtooth threads, the contact area between the male thread 45 and the female thread 27 can be increased. This improves the pressure resistance of the housing 10 against the internal pressure of the oil filter.
[0029] Furthermore, since the frictional force acting between the male thread 45 and the female thread 27 is increased, the overall length of the male thread 45 and the female thread 27 can be shortened even further. Therefore, attaching and detaching the cap 40 to the case 20 becomes even easier.
[0030] (4) Multiple female threads 27 are arranged in the circumferential direction of the case 20 at intervals from each other. Multiple male threads 45 are arranged in the circumferential direction of the cap 40 at intervals from each other.
[0031] This configuration allows for a shorter overall length of the male thread 45 and female thread 27 while maintaining a sufficient contact area between them. In other words, it reduces the rotation angle required to attach and detach the cap 40 to the case 20. Therefore, attaching and detaching the cap 40 to the case 20 becomes much easier.
[0032] (5) The key portion 47 is provided on only one of the multiple male threads 45. Providing a key portion 47 on each of the multiple male threads 45 may lead to the following inconveniences. Specifically, due to variations in the manufacturing of the cap 40, the timing at which the key portion 47 engages with the front end 28 of the female thread 27 will differ among the male threads 45, causing inconvenience such as the operator feeling uncomfortable when attaching or detaching the cap 40 to the case 20.
[0033] In this regard, with the above configuration, since the key portion 47 is provided on only one of the multiple male screw threads 45, the occurrence of the aforementioned problems can be suppressed. (6) The key portion 47 has a front inclined surface 48 that is inclined such that the protrusion height in the width direction decreases as it moves towards the front.
[0034] The presence of a key portion 47 at the front end of the male thread 45 makes it easier for the key portion 47 to catch on the rear end 29 of the female thread 27. As a result, a large torque may be required when screwing the cap 40 onto the case 20.
[0035] In this regard, with the above configuration, since the key portion 47 has a front inclined surface 48, the key portion 47 is less likely to get caught on the rear end 29 of the female screw thread 27. Therefore, the cap 40 can be easily screwed onto the case 20.
[0036] Furthermore, by appropriately setting the inclination angle of the front inclined surface 48, the torque required when screwing the cap 40 onto the case 20 can be appropriately set. (7) The key portion 47 is located behind the front inclined surface 48 and has a rear inclined surface 49 that is inclined such that the protrusion height in the width direction increases as it is towards the front.
[0037] With this configuration, since the key portion 47 has a rear inclined surface 49, the torque required to remove the cap 40 from the case 20 can be appropriately set by appropriately setting the inclination angle of the rear inclined surface 49.
[0038] (8) The inclination angle of the rear inclined surface 49 is greater than the inclination angle of the front inclined surface 48. With this configuration, the relatively small inclination angle of the front inclined surface 48 makes it easier to screw the cap 40 onto the case 20. Also, the relatively large inclination angle of the rear inclined surface 49 makes it less likely for the cap 40 to loosen on the case 20.
[0039] <Variation> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.
[0040] The inclination angle of the rear inclined surface 49 may be the same as the inclination angle of the front inclined surface 48, or it may be smaller than the inclination angle of the front inclined surface 48. The key portion 47 may not have a rear inclined surface 49. That is, the surface corresponding to the rear inclined surface 49 may extend along the width direction of the male screw thread 45.
[0041] The key portion 47 may not have a front inclined surface 48. That is, the surface corresponding to the front inclined surface 48 may extend along the direction in which the male screw threads 45 extend. • Key portions 47 may be provided on all four male threads 45.
[0042] The number of female threads (27) and male threads (45) can be changed as appropriate. The female thread 27 and male thread 45 may be present only once each. The female thread 27 and male thread 45 may also be of other shapes, such as round-toothed threads or trapezoidal-toothed threads.
[0043] • The restrictive projection 31 can be omitted. The shapes of the female threads 27 and male threads 45 of this disclosure can also be applied to housing cases and caps other than oil filters.
[0044] <Note> The above embodiment includes the configuration described in the following appendix. [Note 1] An element-replaceable oil filter comprising: a housing that includes a cylindrical case with a closed bottom on one side, which is detachably configured to be attached to an internal combustion engine and has an inlet for oil from the internal combustion engine and an outlet for oil from which oil flows out, and a cylindrical cap with a closed bottom on one side that is detachably configured to be attached to the case; and an element housed inside the housing for filtering the oil, The inner circumferential surface of the case is provided with a plurality of female threads that extend spirally around the central axis of the case and are parallel to each other. The outer circumferential surface of the cap is provided with male threads that extend spirally around the central axis of the cap and engage with the female threads. When the forward direction of screwing the cap into the case is defined as the forward direction, The front end of the male thread is provided with a key portion that protrudes in the width direction of the male thread and is configured to engage with the front end of the female thread adjacent to the male thread in the axial direction of the cap. Element-replaceable oil filter.
[0045] [Note 2] On the inner circumferential surface of the case, in front of the female thread, is provided a regulating projection that abuts against the front end of the male thread, thereby restricting the forward movement of the cap relative to the case. The element-replaceable oil filter described in Appendix 1.
[0046] [Note 3] The male thread and the female thread are sawtooth threads. An element-replaceable oil filter as described in Appendix 1 or Appendix 2.
[0047] [Note 4] Multiple female threads are arranged in the circumferential direction of the case, spaced apart from each other. Multiple male threads are arranged in the circumferential direction of the cap, spaced apart from each other. An element-replaceable oil filter as described in any one of the appendices 1 through 4.
[0048] [Note 5] The key portion is provided on only one of the multiple male threads. The element-replaceable oil filter described in Appendix 4.
[0049] [Note 6] The key portion has a front inclined surface that slopes such that the protruding height in the width direction decreases towards the front. An element-replaceable oil filter as described in any one of the notes 1 through 5.
[0050] [Note 7] The key portion is located behind the front inclined surface and has a rear inclined surface that is inclined such that the protrusion height in the width direction increases as it is towards the front. The element-replaceable oil filter described in Appendix 6.
[0051] [Note 8] The inclination angle of the rear inclined surface is greater than the inclination angle of the front inclined surface. The element-replaceable oil filter described in Appendix 7. [Explanation of Symbols]
[0052] 10… Housing 20... cases 21...Bottom wall 22...Peripheral wall 23…Aperture 24…Inlet 25... Outlet 26…Support protrusion 27... Female thread 28…front end 29...rear end 31…Restriction protrusion 32…Regulatory aspects 40... Cap 41...Bottom wall 42...Peripheral wall 43…Aperture 44...Support groove 45... Male screw thread 47...Key section 48...Front slope 49…Rear side slope 50...Element 60...Sealing material
Claims
1. An element-replaceable oil filter comprising: a housing that includes a cylindrical case with a closed bottom on one side, which is detachably configured to be attached to an internal combustion engine and has an inlet for oil from the internal combustion engine and an outlet for oil from which oil flows out, and a cylindrical cap with a closed bottom on one side that is detachably configured to be attached to the case; and an element housed inside the housing for filtering the oil, The inner circumferential surface of the case is provided with a plurality of female threads that extend spirally around the central axis of the case and are parallel to each other. The outer circumferential surface of the cap is provided with male threads that extend spirally around the central axis of the cap and engage with the female threads. When the forward direction of screwing the cap into the case is defined as the forward direction, The front end of the male thread is provided with a key portion that protrudes in the width direction of the male thread and is configured to engage with the front end of the female thread adjacent to the male thread in the axial direction of the cap. Element-replaceable oil filter.
2. On the inner circumferential surface of the case, in front of the female thread, is provided a regulating projection that abuts against the front end of the male thread, thereby restricting the forward movement of the cap relative to the case. The element-replaceable oil filter according to claim 1.
3. The male thread and the female thread are sawtooth threads. The element-replaceable oil filter according to claim 1.
4. Multiple female threads are arranged in the circumferential direction of the case, spaced apart from each other. Multiple male threads are arranged in the circumferential direction of the cap, spaced apart from each other. An element-replaceable oil filter according to any one of claims 1 to 3.
5. The key portion is provided on only one of the multiple male threads. The element-replaceable oil filter according to claim 4.
6. The key portion has a front inclined surface that slopes such that the protruding height in the width direction decreases towards the front. The element-replaceable oil filter according to claim 1.
7. The key portion is located behind the front inclined surface and has a rear inclined surface that is inclined such that the protrusion height in the width direction increases as it is towards the front. The element-replaceable oil filter according to claim 6.
8. The inclination angle of the rear inclined surface is greater than the inclination angle of the front inclined surface. The element-replaceable oil filter according to claim 7.