A sealing member for sealing the space between the valve body and valve seat of a pressure damper that reduces the pressure of the liquid supplied from a liquid storage means to a liquid injection head in a liquid injection device, and a liquid injection device equipped with a pressure damper including the sealing member.

Abstract

To provide a sealing member that can properly seal a valve in a pressure damper. [Solution] The sealing member 124 seals the space between the valve body 121 and the valve seat 123 in a valve of a pressure damper that reduces the pressure of the liquid supplied from the liquid storage means to the liquid injection head in a liquid injection device. The sealing member 124, in its pre-deformation state, comprises an outer circumference 124a having an outer diameter larger than the inner diameter of the side wall 111a of the first liquid chamber in which the valve body 121 is housed, an inner circumference 124b having a contact surface 124bb with the valve seat 123 provided on the bottom 111b of the first liquid chamber, and a connecting portion 124c that bends the outer circumference 124a and the inner circumference 124b. The sealing member 124 is configured such that when the inner circumference 124b is bent relative to the outer circumference 124a when it is installed in the first liquid chamber, the contact area between the valve seat 123 and the contact surface 124bb of the inner circumference 124b increases.

Description

Technical Field

[0001] The present invention relates to a sealing member that seals between a valve body and a valve seat of a pressure damper that reduces the pressure of a liquid supplied from liquid storage means to a liquid injection head in a liquid injection device, and a liquid injection device including the pressure damper including the sealing member.

Background Art

[0002] Conventionally, in a liquid injection device such as an inkjet printer, when a liquid is pumped from a liquid storage means such as an ink cartridge or an ink tank to a liquid injection head such as an inkjet head through a liquid supply path, a pressure damper for reducing the pressure of the liquid pumped at a high pressure from the liquid storage means before supplying the liquid to the liquid injection head is provided in the liquid supply path. For example, Citation 1 discloses a valve unit that functions as such a pressure damper.

[0003] In a conventional pressure damper, even when the valve body closes the communication hole and the liquid does not flow from the first liquid chamber where the liquid is first supplied from the liquid storage means to the second liquid chamber that supplies the liquid to the liquid injection head through the communication hole, the liquid may flow from the first liquid chamber to the second liquid chamber through the back surface and / or side surface (that is, the surface that does not contact the valve body) of the sealing member that seals between the valve body and the communication hole.

[0004] For example, a conventional pressure damper 500, as shown in Figure 7, has the same configuration as the pressure damper 100 according to the above embodiment, except that it uses a sealing member 524 instead of the sealing member 124, which has a shape that conforms to the side, bottom, and valve seat of the first liquid chamber. However, due to manufacturing precision issues, if the outer diameter of the sealing member 524 is smaller than expected from the inner diameter of the side wall 111a of the first liquid chamber 111, a gap large enough for liquid to flow may be created between the sealing member 524 and the side wall 111a of the first liquid chamber 111. Also, if the outer diameter of the sealing member 524 is larger than expected from the inner diameter of the side wall 111a of the first liquid chamber 111, the entire sealing member 524 may be distorted, causing part or all of the sealing member 524 to lift away from the valve seat 123, creating a gap large enough for liquid to flow between the sealing member 524 and the valve seat 123.

[0005] Furthermore, if liquid continuously flows from the first liquid chamber to the second liquid chamber through the back and / or sides of the sealing member that seals the space between the valve body and the communication hole, deposits contained in the liquid, such as pigment particles contained in paint, will accumulate on the back and / or sides of the sealing member. This widens the gap on the back and / or sides of the sealing member, increasing the amount of liquid leaking out through the gap and significantly impairing the sealing valve function of the pressure damper. As a result, the sealing member needs to be cleaned frequently, increasing maintenance costs. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2019-104175 [Overview of the project] [Problems that the invention aims to solve]

[0007] In view of the above, the present invention aims to provide a sealing member that can perform suitable sealing of a valve in a pressure damper. [Means for solving the problem]

[0008] A sealing member according to a first aspect of the present invention is A sealing member for sealing the space between the valve body and valve seat of a pressure damper that reduces the pressure of the liquid supplied from a liquid storage means to a liquid injection head in a liquid injection device, The sealing member comprises, in its pre-deformation state, an outer circumference having an outer diameter larger than the inner diameter of the side wall of the liquid chamber in which the valve body is housed, an inner circumference having a contact surface with the valve seat provided on the bottom of the liquid chamber, and a connecting portion that flexibly connects the outer circumference and the inner circumference. The sealing member is configured such that when the inner circumference is bent relative to the outer circumference when it is installed in the liquid chamber, the contact area between the valve seat and the contact surface of the inner circumference increases.

[0009] According to the above configuration, since a protrusion is provided on the outer circumference of the sealing member, the liquid tightness between the sealing member and the side wall of the liquid chamber is improved. Furthermore, since a flexible connecting portion is provided between the outer circumference and the inner circumference of the sealing member, when the valve body presses against the sealing member, the inner circumference tilts relative to the outer circumference, causing the inner circumference to come into close contact with the valve seat, thus improving the liquid tightness between the inner circumference and the valve seat.

[0010] The inner circumference has an engaging portion that engages with the side surface of the valve seat, In the closed valve state, the engaging portion on the inner circumference may be in contact with the bottom of the liquid chamber.

[0011] According to the above configuration, the engaging portion on the inner circumference and the bottom portion are securely in contact, improving the liquid-tightness between them.

[0012] In the closed valve state, the outer circumference may be in contact with the bottom.

[0013] According to the above configuration, the outer periphery and the bottom are securely in contact, improving the liquid-tightness between them.

[0014] When the sealing member is installed in the liquid chamber, the contact surface of the inner circumference is separated from the upper surface of the valve seat. The contact surface of the inner peripheral portion may be provided with a protruding portion having a radius of curvature that is 3 to 5 times the protrusion height.

[0015] According to the above configuration, even if the inner peripheral portion is bent at various angles with respect to the outer peripheral portion, the protrusion of the contact surface will contact the upper surface of the valve seat with a contact area of a certain level or more. Therefore, it is possible to cope with various sizes of gaps that occur between the contact surface of the inner peripheral portion of the sealing member and the upper surface of the valve seat due to the processing dimensions or distortion of the sealing member.

[0016] The liquid injection device according to the second aspect of the present invention includes a pressure damper that includes the sealing member according to the first aspect of the present invention.

[0017] According to the above configuration, the cleaning frequency of the sealing member can be reduced, and the maintenance cost can be suppressed.

Effects of the Invention

[0018] According to the present invention, suitable sealing of the valve can be performed in the pressure damper.

Brief Description of the Drawings

[0019] [Figure 1] Schematic cross-sectional view of a pressure damper according to an embodiment of the present invention. (a) is a cross-sectional view of the pressure damper in the valve-closed state, (b) is an enlarged view near the valve body in the valve-closed state, (c) is a cross-sectional view of the pressure damper in the valve-open state, and (d) is an enlarged view near the valve body in the valve-open state. [Figure 2] Perspective view ((a)) and cross-sectional view ((b)) of a sealing member of a pressure damper according to an embodiment of the present invention. [Figure 3] Cross-sectional view of a sealing member of a pressure damper according to an embodiment of the present invention. (a) is a cross-sectional view of the sealing member before being attached to the pressure damper, (b) is a cross-sectional view of the sealing member when bent before being attached to the pressure damper, (c) is a cross-sectional view of the sealing member in the valve-open state after being attached to the pressure damper, and (d) is a cross-sectional view of the sealing member in the valve-closed state after being attached to the pressure damper. [Figure 4] Cross-sectional view of a sealing member of a modified example of the present invention. [Figure 5]Cross-sectional view of a sealing member according to a modified example of the present invention. (a) shows a cross-sectional view of the sealing member before being attached to the pressure damper, and (b) shows a cross-sectional view of the sealing member in the valve-closed state after being attached to the pressure damper. [Figure 6] Cross-sectional view of a sealing member according to a modified example of the present invention. (a) shows a cross-sectional view of the sealing member before being attached to the pressure damper, and (b) shows a cross-sectional view of the sealing member in the valve-closed state after being attached to the pressure damper. [Figure 7] Enlarged view of the vicinity of the sealing member of a conventional pressure damper.

Mode for Carrying Out the Invention

[0020] The pressure damper 100 according to an embodiment of the present invention will be described below with reference to the drawings. The pressure damper 100 is provided on a liquid supply path, particularly immediately before a liquid injection head, in order to decompress the liquid that is pumped from a liquid storage means for storing the liquid to the liquid injection head that injects the liquid to a target through the liquid supply path in a liquid injection device such as a printing device using an inkjet method.

[0021] For example, the liquid injection device is a device that injects liquid by an inkjet method, and may be, for example, an inkjet printer. In this case, the liquid is ink, the liquid storage means is an ink tank or an ink cartridge connected to a pump for pumping the ink, and the liquid injection head is an inkjet head. Further, the liquid injection head may be provided on a carriage for moving the liquid injection head along the surface of the target to which the liquid is to be injected, and furthermore, the pressure damper 100 may also be provided on this carriage.

[0022] (Configuration of the pressure damper 100) As shown in Figures 1(a) to (d), the pressure damper 100 includes a valve body 110, which contains a first liquid chamber 111 communicating with a liquid storage means, a first liquid flow path 112 through which liquid flows from the liquid storage means to the first liquid chamber 111, a second liquid chamber 113 communicating with a liquid injection head, a second liquid flow path 114 through which liquid flows from the second liquid chamber 113 to the liquid injection head, and a communication hole 115 connecting the first liquid chamber 111 and the second liquid chamber 113. The valve body 110 may be formed as a single unit or may be constructed by combining multiple components. During operation, the first liquid chamber 111, the second liquid chamber 113, and the communication hole 115 are filled with liquid supplied from the liquid storage means. In the figures, for simplification and visibility, the liquid is not shown and no hatching is applied.

[0023] The first liquid chamber 111 is substantially cylindrical and comprises a side wall 111a, a bottom portion 111b surrounding the communication hole 115, and an opening 111c that opens on the opposite side of the bottom portion 111b. The opening 111c is sealed liquid-tight by a lid 120 that fits onto it. For example, the opening 111c and the lid 120 are formed to fit together by press-fitting or screw-type mechanisms.

[0024] The first liquid chamber 111 houses a disc-shaped valve body 121 that closes the communication hole 115 and a first elastic member 122 that biases the valve body 121 toward the second liquid chamber 113. The first elastic member 122 is, for example, a spring such as a compression coil spring. For example, one end of the first elastic member 122 is fixed to an elastic member fixing part 120a provided on the inner surface of the lid 120 (the surface facing the first liquid chamber 111), and the other end is fixed to an elastic member fixing part 121a provided on the surface of the valve body 121 facing the lid 120. For example, the elastic member fixing part 121a consists of a plurality of arc-shaped walls protruding from the valve body 121 and is slidably held by a cylindrical holding part 120b protruding from the lid 120.

[0025] A valve seat 123 is provided on the bottom portion 111b to receive the valve body 121. For example, the valve seat 123 is formed integrally with the bottom portion 111b. An annular sealing member 124 is positioned on the valve seat 123 to seal the space between the valve body 121 and the communication hole 115 when the valve body 121 closes the communication hole 115. In addition, to prevent the sealing member 124 from floating up from the valve seat 123 due to the movement of liquid in the first liquid chamber 111, the sealing member 124 is held down by a substantially cylindrical push member 125 with both ends open. Details of the sealing member 124 will be described later. The push member 125 abuts against the inner surface of the lid 120 (the surface facing the first liquid chamber 111) at one end and against the sealing member 124 at the other end. The push member 125 is provided with a through hole 125a through which the first liquid flow path 112 opens.

[0026] The second liquid chamber 113 is substantially cylindrical and comprises a side wall 113a, a bottom portion 113b surrounding the communication hole 115, and an opening 113c that opens on the opposite side of the bottom portion 113b. The opening 113c is liquid-tightly sealed by a flexible member 130, which is a flexible film. The flexible member 130 is fixed around the edge of the opening 113c by heat welding or the like.

[0027] A valve stem 131, fixed to a flexible member 130, is housed within the second liquid chamber 113. The valve stem 131 moves through the communication hole 115 in conjunction with the deflection of the flexible member 130 due to fluctuations in the liquid pressure in the second liquid chamber 113. The valve stem 131 passes through the communication hole 115 at one end and is equipped with a pressure receiving plate 131a at the other end. The pressure receiving plate 131a is fixed to the inner surface of the flexible member 130 (the surface facing the second liquid chamber 113) by heat welding or the like. In order to prevent the pressure receiving plate 131a from tilting as much as possible in response to the deflection of the flexible member 130, and to allow it to move while maintaining a right angle to the center line of the communication hole 115, for example, the pressure receiving plate 131a is biased away from the first liquid chamber 111 by a second elastic member 132. The second elastic member 132 is, for example, a spring such as a compression coil spring. For example, one end of the second elastic member 132 is fixed to an elastic member fixing part 131b provided on the surface of the pressure receiving plate 131a of the valve stem 131 facing the bottom 113b of the second liquid chamber 113, and the other end is fixed to an elastic member fixing part 113d provided on the bottom 113b of the second liquid chamber 113.

[0028] The materials of the valve body 110, lid 120, valve element 121, valve seat 123, push member 125, and valve stem 131 are, independently, metal or resin. The materials of the first elastic member 122 and the second elastic member 132 are any elastic material, for example, metal.

[0029] (Operation of pressure damper 100) When no liquid is being sprayed from the liquid injection head, the valve body 121 is biased toward the second liquid chamber 113 by the first elastic member 122 within the first liquid chamber 111. As a result, as shown in Figures 1(a) and (b), the valve body 121 moves to the closed position and contacts the sealing member 124 on the valve seat 123, closing the communication hole 115. This prevents liquid from flowing from the first liquid chamber 111 to the second liquid chamber 113. This operation of the pressure damper 100 is called valve closing operation.

[0030] On the other hand, when liquid is being sprayed from the liquid injection head, the amount of liquid in the second liquid chamber 113 decreases, and the second liquid chamber 113 becomes negatively pressurized. Consequently, the flexible member 130 bends, and the central part of the flexible member 130 and the pressure-receiving plate 131a are displaced toward the first liquid chamber against the second elastic member 132. The bent central part of the flexible member 130 and the pressure-receiving plate 131a press the valve stem 131 against the valve body 121, and the valve stem 131 pushes the valve body 121 against the first elastic member 122. As a result, as shown in Figures 1(b) and (d), the valve body 121 separates from the sealing member 124 and the valve seat 123, opening the communication hole 115. This allows liquid to flow from the first liquid chamber 111 to the second liquid chamber 113. This operation of the pressure damper 100 is called the valve opening operation.

[0031] (Configuration of sealing member 124) As shown in Figure 2(a), the sealing member 124 is an annular member configured to seal the space between the valve body 121 and the communication hole 115 when the valve body 121 closes the communication hole 115. The material of the sealing member 124 is any elastic material, such as ethylene propylene diene rubber (EPDM), butyl rubber, or silicone rubber. The sealing member 124 also has a Shore A hardness of, for example, 30 to 60 degrees, preferably 35 to 55 degrees, and more preferably 40 to 50 degrees.

[0032] As shown in Figures 2(b) and 3(a) to 3(d), the sealing member 124 comprises an outer circumference 124a, an inner circumference 124b, and a connecting portion 124c that flexibly connects the outer circumference 124a and the inner circumference 124b. The connecting portion 124c is formed to be thinner than the outer circumference 124a and the inner circumference 124b, and as shown in Figure 3(d), it allows the sealing member 124 to deform such that the inner circumference 124b tilts relative to the outer circumference 124a when the valve body 121 presses on the sealing member 124.

[0033] The outer peripheral portion 124a abuts against the side wall 111a of the first liquid chamber 111 when the sealing member 124 is inserted into the first liquid chamber 111, but does not abut against the bottom portion 111b. The outer peripheral portion 124a further comprises a protruding portion 124aa that protrudes toward the side wall 111a and a non-protruding portion 124ab that does not protrude.

[0034] As shown in Figures 2(b) and 3(a), if W1 is the inner diameter of the portion of the side wall 111a of the first liquid chamber 111 that abuts the outer circumference 124a, then in the outer circumference 124a before deformation, the outer diameter W4 of the protruding portion 124aa is larger than W1, and the outer diameter W5 of the non-protruding portion 124ab is less than or equal to W1. Therefore, when the sealing member 124 is inserted into the first liquid chamber 111, as shown in Figure 3(a), the protruding portion 124aa catches on the side wall 111a of the first liquid chamber 111, and as shown in Figure 3(c), the entire side surface of the outer circumference 124a conforms to the side wall 111a, and deforms so that, for example, in the cross-section of the sealing member 124 along the center line, the angle between the side surface of the protruding portion 124aa and the side surface of the non-protruding portion 124ab approaches 180 degrees, for example, so that it becomes flush.

[0035] At this time, the protrusion 124aa pushes the side wall 111a with a predetermined force due to its restoring force. As a result, the liquid tightness between the outer periphery 124aa and the side wall 111a, in particular, the liquid tightness between the protrusion 124aa and the side wall 111a, is improved compared to the case where the protrusion 124aa is not present.

[0036] Furthermore, when the outer periphery 124a is pressed down by the pressing member 125, the pressing force (black arrow in the figure) compresses the outer periphery 124a, causing a slight deformation (white arrow in the figure) along the direction perpendicular to the pressing force to the outer periphery 124a, particularly the protruding portion 124aa. This deformation increases the force with which the outer periphery 124a, particularly the protruding portion 124aa, presses against the side wall 111a. As a result, the liquid-tightness between the outer periphery 124a and the side wall 111a, particularly between the protruding portion 124aa and the side wall 111a, is further improved.

[0037] As shown in Figure 3(d), the inner circumference 124b is sandwiched between the valve body 121 and the valve seat 123 when the valve body 121 closes the communication hole 115. The inner circumference 124b is formed such that, when viewed from the direction in which the sealing member 124 is inserted into the first liquid chamber 111, most of it is contained within the region outside the communication hole 115 and inside the outer circumference of the valve body 121. For example, if the inner diameter of the communication hole 115 is W2 and the outer diameter of the valve body 121 is W3, the inner circumference 124b has an inner diameter approximately the same as W2, and in particular larger than W2, and an outer diameter approximately the same as W3, and in particular smaller than W3, when viewed from the direction in which the sealing member 124 is inserted into the first liquid chamber 111.

[0038] The inner circumference 124b includes a contact surface 124ba that makes surface contact with the valve body 121 when the valve body 121 closes the communication hole 115, a contact surface 124bb that makes surface contact with the upper surface 123a (the surface facing the valve body 121) of the valve seat 123 when the valve body 121 closes the communication hole 115, and an engaging portion 124bc that engages with the inner side surface 123b of the valve seat 123 and the bottom 111b of the first liquid chamber 111 when the valve body 121 closes the communication hole 115. As can be seen by comparing the cross-section of the engaging portion 124bc of the sealing member 124 with the dotted line of the valve seat 123 when the inner circumference 124b is tilted with respect to the outer circumference 124a to the same extent as in Figure 3(d) shown in Figure 3(b), and the contact surface 124bb is aligned with the dotted line on the inner surface of the first liquid chamber 111, when the valve body 121 closes the communication hole 115, the engaging portion 124bc presses against the side surface 123b of the valve seat 123 and the bottom 111b of the first liquid chamber 111, as shown in Figure 3(d).

[0039] (Effects of the present invention) In conventional pressure dampers, even when the valve body closes the communication hole and prevents liquid from flowing through the communication hole from the first liquid chamber, where liquid is initially supplied from the liquid storage means, to the second liquid chamber, where liquid is supplied to the liquid injection head, liquid may still flow from the first liquid chamber to the second liquid chamber through the back and / or side (i.e., the surface that does not come into contact with the valve body) of the sealing member that seals the space between the valve body and the communication hole.

[0040] For example, a conventional pressure damper 500, as shown in Figure 7, has the same configuration as the pressure damper 100 according to the above embodiment, except that it uses a sealing member 524 instead of the sealing member 124, which has a shape that conforms to the side, bottom, and valve seat of the first liquid chamber. However, due to manufacturing precision issues, if the outer diameter of the sealing member 524 is smaller than expected from the inner diameter of the side wall 111a of the first liquid chamber 111, a gap large enough for liquid to flow may be created between the sealing member 524 and the side wall 111a of the first liquid chamber 111. Also, if the outer diameter of the sealing member 524 is larger than expected from the inner diameter of the side wall 111a of the first liquid chamber 111, the entire sealing member 524 may be distorted, causing part or all of the sealing member 524 to lift away from the valve seat 123, creating a gap large enough for liquid to flow between the sealing member 524 and the valve seat 123.

[0041] Furthermore, if liquid continuously flows from the first liquid chamber to the second liquid chamber through the back and / or side of the sealing member that seals the space between the valve body and the communication hole, deposits contained in the liquid, such as pigment particles contained in paint, will accumulate on the back and / or side of the sealing member. This will widen the gap on the back and / or side of the sealing member, increasing the amount of liquid leaking out through the gap and significantly impairing the sealing valve function of the pressure damper.

[0042] On the other hand, according to the above embodiment, since a protrusion 124aa is provided on the outer periphery 124a of the sealing member 124, the liquid tightness between the sealing member 124 and the side wall 111a of the first liquid chamber 111 is improved. In particular, even if the deformation of the sealing member 124 could create a gap large enough for liquid to flow between the outer periphery 124a of the sealing member 124 and the side wall 111a of the first liquid chamber 111, the deformation is absorbed by the deformation of the protrusion 124aa because W4>W1>W5, so that the outer periphery 124a and the side wall 111a are in close contact when the valve is closed.

[0043] Furthermore, since a flexible connecting portion 124c is provided between the outer circumference 124a and the inner circumference 124b of the sealing member 124, when the valve body 121 presses the sealing member 124, the inner circumference 124b tilts relative to the outer circumference 124a, causing the inner circumference 124b to come into close contact with the valve seat 123, thereby improving the liquid-tightness between the inner circumference 124b and the valve seat 123. In particular, even if the deformation of the sealing member 124 could create a gap between the inner circumference 124b of the sealing member 124 and the valve seat 123, for example, between the contact surface 124bb and the upper surface 123a of the valve seat 123 and / or between the engaging portion 124bc and the side surface 123b of the valve seat 123, the deformation is absorbed by the bending at the connecting portion 124c, so that the inner circumference 124b and the valve seat 123 come into close contact when the valve is closed.

[0044] Furthermore, when the valve is closed, if both the engaging portion 124bc and the outer portion 124a of the inner circumference 124b of the sealing member 124 abut against the bottom 111b of the first liquid chamber 111, a gap may form between the contact surface 124bb of the inner circumference 124b of the sealing member 124 and the upper surface 123a of the valve seat 123 if the length of one or both of the engaging portion 124bc and the outer portion 124a of the inner circumference 124b is longer than expected, or if the sealing member 124 is distorted. However, according to the above embodiment, when the valve is closed, the engaging portion 124bc of the inner circumference 124b of the sealing member 124 abuts against the bottom 111b of the first liquid chamber 111, but the outer portion 124a of the sealing member 124 does not abut against the bottom 111b. Therefore, as described above, even if a gap occurs between the contact surface 124bb of the inner circumference 124b of the sealing member 124 and the upper surface 123a of the valve seat 123 due to the processing dimensions or distortion of the sealing member 124, this gap is filled by the deeper bending at the connecting portion 124c, so that the inner circumference 124b and the valve seat 123 are in close contact. In addition, since the engaging portion 124bc of the inner circumference 124b abuts against the bottom 111b of the first liquid chamber 111, liquid tightness between the two is guaranteed.

[0045] (modified version) In the above-described embodiment, the pressure damper 100, excluding the sealing member 124, can be configured arbitrarily according to well-known technology, as long as it is compatible with the sealing member 124.

[0046] For example, the pressure damper 100 may include a first liquid chamber from which liquid is supplied from a liquid storage means, a second liquid chamber for which liquid is supplied to a liquid injection head, a communication hole for liquid communication between the first and second liquid chambers, a flexible member that forms part of the wall surface of the second liquid chamber and is displaced based on pressure fluctuations in the second liquid chamber, a valve body configured to move between a closed position that closes the communication hole and an open position that opens the communication hole, and an elastic member that biases the valve body to always be held in the closed position, and displaces the valve body from the posture that holds it in the closed position when it receives a pressing force from the flexible member due to the inward displacement of the flexible member in the second liquid chamber. In this case, the valve body moves from the closed position to the open position based on the inward displacement of the flexible member in the second liquid chamber.

[0047] The sealing member 124, in its pre-deformation state, comprises an outer circumference having an outer diameter larger than the inner diameter of the side wall of the first liquid chamber of the pressure damper, an inner circumference having a contact surface with a valve seat provided on the bottom of the first liquid chamber, and a connecting portion that flexibly connects the outer circumference and the inner circumference, and is configured such that when the sealing member 124 is installed in the first liquid chamber, bending the inner circumference relative to the outer circumference increases the contact area between the valve seat and the contact surface of the inner circumference.

[0048] In the above embodiment, the protrusions 124aa of the outer periphery 124a are formed on the side of the outer periphery 124a that abuts against the push-in member 125, but the position, number, and shape of the protrusions 124aa on the outer periphery 124a are arbitrary. For example, as shown in Figure 4, the protrusions 124aa may be formed in the center of the side surface of the outer periphery 124a. Regardless of the position, number, and shape of the protrusions 124aa on the outer periphery 124a, if the outer diameter of the protrusions 124aa is larger than the inner diameter of the side wall 111a of the first liquid chamber 111, the liquid tightness between the sealing member 124 and the side wall 111a of the first liquid chamber 111 is improved.

[0049] In the above embodiment, when the valve is closed, the engaging portion 124bc of the inner circumference 124b of the sealing member 124 abuts against the bottom 111b of the first liquid chamber 111, and the outer circumference 124a of the sealing member 124 does not abut against the bottom 111b. However, as shown in Figure 5, when the valve is closed, the engaging portion 124bc of the inner circumference 124b of the sealing member 124 does not abut against the bottom 111b of the first liquid chamber 111, and the outer circumference 124a of the sealing member 124 abuts against the bottom 111b. In this modified example, as described above, if a gap occurs between the sealing member 124 and the valve seat 123 due to the processing dimensions or distortion of the sealing member 124, for example, between the contact surface 124bb of the inner circumference 124b of the sealing member 124 and the upper surface 123a of the valve seat 123 and / or between the engaging portion 124bc of the sealing member 124 and the side surface 123b of the valve seat 123, this gap can be filled by a deeper bend at the connecting portion 124c, thereby ensuring a tight seal between the inner circumference 124b and the valve seat 123. Furthermore, since the outer circumference 124a is in contact with the bottom 111b of the first liquid chamber 111, liquid tightness between the two is guaranteed.

[0050] Furthermore, the sealing member 124 may be configured such that, in the closed valve state, both the engaging portion 124bc of the inner circumference 124b and the outer circumference 124a of the sealing member 124 abut against the bottom 111b of the first liquid chamber 111. In this case, if the length of one or both of the engaging portion 124bc and the outer circumference 124a of the inner circumference 124b is longer than expected, a gap may form between the contact surface 124bb of the inner circumference 124b of the sealing member 124 and the upper surface 123a of the valve seat 123. However, this gap is filled as the sealing member 124 flexes toward the valve seat 123 via the connecting portion 124c, so that in the closed valve state, the inner circumference 124b and the valve seat 123 are in close contact.

[0051] Furthermore, the sealing member 124 may be configured such that, in the closed valve state, both the engaging portion 124bc of the inner circumference 124b and the outer circumference 124a of the sealing member 124 do not come into contact with the bottom 111b of the first liquid chamber 111. Even in this case, the strain of the sealing member 124 is absorbed by the bending at the connecting portion 124c, so even if strain occurs in the sealing member 124, the inner circumference 124b and the valve seat 123 will be in close contact in the closed valve state.

[0052] Furthermore, in the closed valve state, if one of the engaging portion 124bc and the outer portion 124a of the inner circumference 124b of the sealing member 124 abuts against the bottom 111b of the first liquid chamber 111 while the other does not, the pressure between one of them and the bottom 111b may be the same as, higher than, or lower than the pressure between the contact surface 124bb of the inner circumference 124b and the upper surface 123a of the valve seat 123. For example, the pressure between the engaging portion 124bc or the outer portion 124a of the inner circumference 124b and the bottom 111b can be increased by reducing the contact area while maintaining contact between the engaging portion 124bc and the outer portion 124a of the inner circumference 124b and the bottom 111b, or by lengthening the engaging portion 124bc or the outer portion 124a of the inner circumference 124b. Conversely, this pressure can be reduced by increasing the contact area while maintaining contact, or by shortening the engaging portion 124bc of the inner circumference 124b or the outer circumference 124a. Also, the pressure between the contact surface 124bb of the inner circumference 124b and the upper surface 123a of the valve seat 123 can be increased by reducing the contact area, weakening the restoring force at the connection portion 124c, or by increasing the inclination of the connection portion 124c toward the valve seat 123 when the sealing member 124 is installed in the first liquid chamber 111, thereby increasing the inclination of the connection portion 124c toward the valve seat 123 when the valve is open. Conversely, this pressure can be reduced by increasing the contact area, strengthening the restoring force at the connection portion 124c, moving the contact surface 124bb away from the valve seat 123 when installed, or by reducing the inclination of the connection portion 124c toward the valve seat 123 when the valve is open. This makes it possible to further improve the liquid-tightness of the areas that require special sealing, such as the space between the engaging portion 124bc of the inner circumference 124b and the bottom portion 111b, the space between the outer circumference 124a and the bottom portion 111b, and the space between the contact surface 124bb of the inner circumference 124b and the upper surface 123a of the valve seat 123.

[0053] Furthermore, when the valve is closed and both the engaging portion 124bc and the outer portion 124a of the inner circumference 124b of the sealing member 124 are in contact with the bottom 111b of the first liquid chamber 111, the pressure between one and the bottom 111b may be the same as the pressure between the other and the bottom 111b, or the pressure between one and the bottom 111b may be higher than the pressure between the other and the bottom 111b. For example, the pressure between the engaging portion 124bc or the outer portion 124a of the inner circumference 124b and the bottom 111b can be increased by reducing the contact area or by lengthening the engaging portion 124bc or the outer portion 124a of the inner circumference 124b, while maintaining contact between the engaging portion 124bc and the outer portion 124a of the inner circumference 124b and the bottom 111b. Conversely, this pressure can be reduced by increasing the contact area while maintaining contact, or by shortening the engaging portion 124bc of the inner circumference 124b or the outer circumference 124a. This makes it possible to further improve the liquid-tightness of the areas that require focused sealing, such as between the engaging portion 124bc of the inner circumference 124b and the bottom 111b, or between the outer circumference 124a and the bottom 111b.

[0054] In the above embodiment, when the sealing member 124 is installed in the first liquid chamber 111, the contact surface 124bb of the inner circumference 124b of the sealing member 124 contacts the upper surface 123a of the valve seat 123. However, as shown in Figure 6, if the contact surface 124bb contacts the upper surface 123a when the inner circumference 124b is bent relative to the outer circumference 124a, then when the sealing member 124 is installed in the first liquid chamber 111, the contact surface 124bb may be separated from the upper surface 123a.

[0055] In the above-described embodiment, the contact surface 124bb of the inner circumference 124b of the sealing member 124 is flat. However, the shape of the contact surface 124bb is arbitrary as long as it can make surface contact with the upper surface 123a of the valve seat 123 with a contact area of ​​a certain size or larger when the valve is closed. As shown in Figure 6, a protrusion 124bba ​​with a small curvature may be provided on the contact surface 124bb. For example, the protrusion 124bba ​​has a radius of curvature that is 3 to 5 times the projection height (thickness of the projection) D, for example, a projection height D of 0.05 to 0.2 mm, more preferably 0.1 to 0.15 mm, and a radius of curvature of 0.3 to 0.6 mm, more preferably 0.4 to 0.5 mm. Even in this case, bending the inner circumference 124b relative to the outer circumference 124a increases the contact area between the valve seat 123 and the contact surface 124bb of the inner circumference 124b.

[0056] As shown in Figure 6, when the sealing member 124 is installed in the first liquid chamber 111, the outer circumference 124a of the sealing member 124 abuts against the bottom 111b, the contact surface 124bb of the inner circumference 124 of the sealing member 124 is separated from the upper surface 123a of the valve seat 123, and the contact surface 124bb may be provided with a protruding portion 124bba ​​with a small curvature. In this modified example, even if the inner circumference 124b is bent at various angles relative to the outer circumference 124a, the protrusion of the contact surface 124bb will contact the upper surface 123a of the valve seat 123 with a contact area of ​​a certain size or larger. As described above, if a gap occurs between the contact surface 124bb of the inner circumference 124b of the sealing member 124 and the upper surface 123a of the valve seat 123 due to the processing dimensions or distortion of the sealing member 124, the size of the gap is not constant. In this modified example, various gap sizes can be accommodated.

[0057] The restoring force of the sealing member 124, which has bent during the valve closing operation, can be adjusted by adjusting the shape, strength, hardness, etc., of the sealing member 124, particularly the inner circumference 124b and / or the connecting portion 124c. For example, if the thickness of the sealing member 124, particularly the thickness of the inner circumference 124b and / or the connecting portion 124c, is made thinner in the direction of movement of the valve body 121, the restoring force will be weakened, and if it is made thicker, it will be increased. Also, for example, if the sealing member 124, particularly the inner circumference 124b and / or the connecting portion 124c, is provided with depressions or through holes in the direction of movement of the valve body 121 and / or continuous or intermittent hollow portions along the circumferential direction, the restoring force will be weakened. Also, for example, if a material with low hardness is used for the sealing member 124, particularly the inner circumference 124b and / or the connecting portion 124c, the restoring force will be weakened, and if a material with high hardness is used, it will be increased. For example, the hardness of a material can be adjusted by increasing or decreasing the amount of hardness modifier added to its raw materials.

[0058] This disclosure allows for various embodiments and modifications without departing from the broad spirit and scope of this disclosure. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of this disclosure. In other words, the scope of this disclosure is indicated by the claims, not by the embodiments. Various modifications made within the scope of the claims and the equivalent significance of the disclosure are considered to be within the scope of this disclosure. [Explanation of symbols]

[0059] 100, 500 pressure damper 110 valve box 111 1st liquid chamber 111a, 113a side wall 111b, 113b bottom 111c, 113c opening 112 First liquid channel 113 2nd liquid chamber 113d, 120a, 121a, 131b Elastic member fixing part 114 Second liquid channel 115 Communication hole 120 Lid 120b Holding part 121 Valve body 122 First Elastic Member 123 valve seat 123a Top side 123b Side 124, 524 Sealing member 124a outer periphery 124aa, 124bba ​​protrusion 124ab Non-protruding part 124b Inner circumference 124ba, 124bb contact surface 124bc Engagement part 124c connection 125 Push-in member 125a through hole 130 Flexible member 131 Valve stem 131a Pressure plate 132 Second Elastic Member

Claims

1. A sealing member for sealing between a valve body and a valve seat in a pressure damper valve that reduces the pressure of the liquid supplied from a liquid storage means to a liquid injection head in a liquid injection device, The sealing member comprises, in its pre-deformation state, an outer circumference having an outer diameter larger than the inner diameter of the side wall of the liquid chamber in which the valve body is housed, an inner circumference having a contact surface with the valve seat provided on the bottom of the liquid chamber, and a connecting portion that flexibly connects the outer circumference and the inner circumference. The sealing member is configured such that when the inner circumference is bent relative to the outer circumference when it is installed in the liquid chamber, the contact area between the valve seat and the contact surface of the inner circumference increases. Sealing member.

2. The inner circumference has an engaging portion that engages with the side surface of the valve seat, In the closed valve state, the sealing member has the engaging portion on its inner circumference in contact with the bottom of the liquid chamber. The sealing member according to claim 1.

3. In the closed valve state, the sealing member has its outer circumference in contact with the bottom. The sealing member according to claim 1.

4. When the sealing member is installed in the liquid chamber, the contact surface of the inner circumference is separated from the upper surface of the valve seat. The contact surface of the inner circumference is provided with a projection having a radius of curvature three to five times the height of the projection. The sealing member according to claim 3.

5. A liquid injection device comprising a pressure damper including a sealing member according to any one of claims 1 to 4.

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