Chemical solution discharge unit

Abstract

To suppress a flow rate change by a patient which is not permitted, in drug solution administration.SOLUTION: A drug solution discharge unit 20 being one embodiment comprises: a flow rate switching mechanism 60 which is stored in a housing 24 and can switch a flow rate of a main channel connected to the discharge channel; and a switching operation part 71 which is linked to the valve body of the flow rate switching mechanism and moves the valve body by operation for switching the flow rate of the flow rate switching mechanism. The switching operation part 71 is arranged in a hole 36 formed on an external face of the housing 24 and is exposed to an external side so as to be operated freely, and an outer peripheral face of the switching operation part 71 is not protruded to the outside of an open end of the hole 36.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a chemical solution discharging unit, and more particularly, to a chemical solution discharging unit used for rapid administration of a chemical solution by self-operation etc.

Background Art

[0002] Conventionally, a chemical solution administration device for continuously administering a chemical solution such as an analgesic or an anesthetic has been known. Also, in a chemical solution administration device, a chemical solution discharging unit for a patient etc. to rapidly administer a chemical solution by self-operation has been known.

[0003] Patent Documents 1 and 2 disclose a chemical solution injection controller (chemical solution discharging unit) in which a pressing operation member is assembled to a housing so as to be pushable, and the chemical solution in a reservoir is discharged into a discharge flow path by a pushing operation of the pressing operation member.

[0004] In the configuration of Patent Document 1, a housing houses a flow rate switching mechanism capable of switching the flow rate of a main flow path connected to the discharge flow path, and an operation part (switching operation part) exposed to the outside of the housing is provided at an end of the housing opposite to the pressing operation member. When the switching operation part is operated, the flow rate of the flow rate switching mechanism is switched.

[0005] In the configuration of Patent Document 2, in order to perform priming for filling a flow path including a reservoir with a chemical solution in a short time, a priming flow path having a larger flow path cross section than a restriction flow path connected in parallel and connected to the reservoir is provided in the housing. Also, the chemical solution discharging unit is provided with a closing mechanism for closing the priming flow path by a pushing operation of a switch into the housing, and an operation preventing member for preventing a pushing operation of the switch. The switch has a closing valve for closing the priming flow path and an operation side end portion provided integrally on the rear side in the pushing direction from the closing valve and having an insertion hole, and the operation preventing member is assembled to the insertion hole.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] International Publication No. 2021 / 015280 [Patent Document 2] International Publication No. 2021 / 015281 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, in the configuration of Patent Document 1, the outer end of the switching operation unit protrudes from the outer surface of the housing, so there is a risk that a patient receiving medication may accidentally touch the switching operation unit and change the flow rate. This may result in the medication not being able to achieve its full effect. Therefore, a structure that can prevent unauthorized flow rate changes by the patient during medication administration is desired.

[0008] Furthermore, if a click sensation is not obtained when the switching mechanism rotates, it becomes difficult to adjust the switching position. On the other hand, in order to obtain a click sensation, it is conceivable to place the switching mechanism inside a hole and engage a projection protruding from the inner circumferential surface of the hole with a groove on the outer circumferential surface of the switching mechanism. However, in this configuration, when the switching mechanism rotates, the projection protruding from the hole presses against the edges of the grooves of the switching mechanism and the outer circumferential surface other than the grooves. This places a large load on the ends of the grooves and parts other than the grooves of the switching mechanism, making them prone to deformation. Over time, the grooves may undergo plastic deformation, potentially reducing the click sensation of the switching mechanism.

[0009] Furthermore, in the configuration of Patent Document 2, an operating block member is inserted into the insertion hole of the switch. In this case, when the deep groove formed in the operating block member and the projection that protrudes into the insertion hole of the operating end of the switch do not face each other in the direction of pushing the switch, and the operating block member and the projection of the switch face each other in the direction of pushing, the operating block member engages with the operating end of the switch, preventing the switch from being pushed into the housing. As a result, even if a force is applied to the switch in the pushing direction before priming, the switch is not pushed in and the shut-off valve does not close the priming passage. On the other hand, when the operating block member is withdrawn so that the deep groove and the projection of the switch face each other in the direction of pushing, the switch can be pushed in.

[0010] However, if a load in the tilting direction is accidentally applied to the operating stopper member before priming, such as during transport of the chemical discharge unit, the operating stopper member may tilt relative to the pulling direction, and the groove of the operating stopper member may face the protrusion of the switch. In this case, if a load in the pushing direction is unintentionally applied to the switch, the switch may be pushed in, and the priming channel may be unintentionally closed before priming. For this reason, a means to prevent the unintentional closing of the priming channel before priming is desirable.

[0011] Furthermore, in the configuration of Patent Document 2, when the user pulls out the operation blocking member to allow the priming channel to be closed, it may not be easy to determine whether or not the switch can be pressed in. This requires the user to pay considerable attention to the pulling operation. For this reason, a means to improve the operability when pulling out the operation blocking member is desired.

[0012] Furthermore, in the configuration of Patent Document 2, the operation blocking member includes an insertion portion that is inserted into the switch and a pull-out operation portion integrally provided with the insertion portion. The pull-out operation portion is a rectangular cylindrical shape with both ends open, one end pressed against the outer surface of the housing and the other end having an outer end opening facing outward.

[0013] However, because the outer end of the cylindrical pull-out section is open, when a user pulls out the operation-blocking member, they may grab and pull on the end of one of the walls forming the outer end opening of the cylindrical section. This can cause the pull-out direction of the operation-blocking member to be tilted relative to the normal direction, resulting in excessive stress between the operation-blocking member and the switch, which may cause deformation of the components. Therefore, there is room for improvement in terms of enhancing the durability of the components of the chemical discharge unit.

[0014] Furthermore, in the configuration of Patent Document 2, when the priming channel is closed by the closing mechanism when the switch is pushed into the housing, it is conceivable that the priming channel is crushed between the inner wall of the housing on the opposite side of the priming channel from the switch and the switch to close the channel. However, if there is a gap between the inner wall on the outer wall side of the housing and the housing, deformation of the inner wall pressed by the switch will occur with long-term use, so there is room for improvement in terms of improving the durability of the chemical discharge unit.

[0015] The object of the present invention is to provide a chemical solution discharge unit that can solve at least one of the above problems. [Means for solving the problem]

[0016] A chemical solution discharge unit according to one aspect of the present invention is a chemical solution discharge unit in which a reservoir is housed in a housing and the chemical solution in the reservoir is discharged into a discharge channel by operation of an operating member, comprising: a flow rate switching mechanism housed in the housing, which is capable of switching the flow rate of a main channel connected to the discharge channel; and a switching operation unit that is interlocked with a valve body of the flow rate switching mechanism and moves the valve body by operation to switch the flow rate of the flow rate switching mechanism, wherein the switching operation unit is arranged in a hole formed in the outer surface of the housing and is exposed to the outside so as to be operable, and the outer peripheral surface of the switching operation unit is configured not to protrude outside the opening end of the hole.

[0017] With the above configuration, it is not easy for the patient to touch and operate the switching mechanism exposed on the outside of the housing. This prevents unauthorized changes in the flow rate by the patient during drug administration.

[0018] In a drug solution discharge unit according to one aspect of the present invention, the switching operation unit may be configured to have a recess into which an operating tool can be inserted and rotated.

[0019] The above configuration makes it easier to manufacture the switching operation unit and allows for increased rigidity, thereby improving reliability.

[0020] A chemical solution discharge unit according to one aspect of the present invention is a chemical solution discharge unit in which a reservoir is housed in a housing and the chemical solution in the reservoir is discharged into a discharge channel by operation of an operating member, comprising: a flow rate switching mechanism housed in the housing and capable of switching the flow rate of a main channel connected to the discharge channel; and a switching operation unit that works in conjunction with the valve body of the flow rate switching mechanism and rotates the valve body by rotation operation to switch the flow rate of the flow rate switching mechanism, wherein the switching operation unit is operably exposed to the outside of the housing and rotatably arranged on the outer surface of the housing, and fixed side protrusions are formed at multiple positions on the outer surface of the housing along the rotation direction of the switching operation unit, and the rotating side protrusions protruding from the outer circumferential surface of the switching operation unit are capable of rotating while riding on the fixed side protrusions.

[0021] With the above configuration, a click sensation can be obtained during operation without placing a large load on the protrusion on the operating side of the switching operation unit, thus suppressing the decrease in the click sensation of the switching operation unit over a long period of time.

[0022] A chemical solution discharge unit according to one aspect of the present invention is a chemical solution discharge unit in which a reservoir is housed in a housing and the chemical solution in the reservoir is discharged into a discharge channel by operation of an operating member, comprising: a priming channel connected to the reservoir and having a larger channel cross-section than a parallel-connected restricting channel; a closing mechanism that closes the priming channel by pushing a switch into the housing; and an operation blocking member that prevents the pushing operation of the switch, wherein the switch includes a closing valve that closes the priming channel and an operating side end having an insertion hole, which is integrally provided on the rear side in the pushing direction from the closing valve, and the operation The blocking member is assembled to the switch so as to be removable from the switch, and when the operating blocking member is inserted into the insertion hole and the groove formed in the operating blocking member and the switch-side projection protruding inward from the insertion hole are not facing each other in the pushing direction, the operating-side end engages with the operating blocking member to prevent the switch from being pushed into the housing, and when the switch is tilted to its maximum extent with respect to the pulling direction before the operating blocking member is removed, the front end of the groove in the pulling direction is located behind the position facing the switch-side projection on the operating blocking member in the pulling direction.

[0023] With the above configuration, even if a load in the tilting direction is mistakenly applied to the operating prevention member before priming, causing the operating prevention member to tilt relative to the pulling direction, the protrusion and groove in the insertion hole will not face the pushing direction. As a result, the switch cannot be pushed in, thus preventing unintended closure of the priming channel before priming.

[0024] A chemical liquid discharge unit according to one aspect of the present invention is a chemical liquid discharge unit in which a reservoir is housed in a housing, and the chemical liquid in the reservoir is discharged into a discharge channel by operating an operating member. The chemical liquid discharge unit includes a priming channel that is connected to the reservoir and has a larger channel cross-section than a restrictor channel connected in parallel, a closing mechanism that closes the priming channel by pushing a switch into the housing, and an operation blocking member that blocks the pushing operation of the switch. The chemical liquid injection controller has a guiding portion that guides the user to feel the state in which the switch can be pushed in.

[0025] According to the above configuration, a user who performs a pulling operation of the operation blocking member can easily determine the state in which the switch can be pushed in, so that the operability when pulling out the operation blocking member can be improved.

[0026] A chemical liquid discharge unit according to one aspect of the present invention is a chemical liquid discharge unit in which a reservoir is housed in a housing, and the chemical liquid in the reservoir is discharged into a discharge channel by operating an operating member. The chemical liquid discharge unit includes a priming channel that is connected to the reservoir and has a larger channel cross-section than a restrictor channel connected in parallel, a closing mechanism that closes the priming channel by pushing a switch into the housing, and an operation blocking member that blocks the pushing operation of the switch. The operation blocking member is assembled to the switch so as to be pullable out from the switch. The operation blocking member includes an insertion portion inserted into the switch and a pulling operation portion provided integrally with the insertion portion. The pulling operation portion includes a cylindrical portion connected to one side in the longitudinal direction of the insertion portion and having one end pressed against the outer peripheral surface of the housing, and an outer wall closing the other end of the cylindrical portion.

[0027] According to the above configuration, when performing the pulling operation of the pulling operation portion, the user has no choice but to grasp the outer periphery of the cylindrical portion, so that it is possible to suppress the pulling direction from being inclined with respect to the normal direction. Thereby, the durability of the chemical liquid discharge unit can be improved.

[0028] A chemical solution discharge unit according to one aspect of the present invention is a chemical solution discharge unit in which a reservoir is housed in a housing and the chemical solution in the reservoir is discharged into a discharge channel by operation of an operating member, comprising: a priming channel connected to the reservoir and having a larger channel cross-section than a parallel-connected restricting channel; and a closing mechanism that closes the priming channel by pushing a switch into the housing, wherein inside the housing, on the side of the priming channel opposite to the pressing portion of the switch in a direction perpendicular to the pushing direction of the switch, a gap is filled so as to linearly connect the outer wall of the housing and the priming channel.

[0029] With the above configuration, deformation of the housing can be prevented when closing the priming channel, thereby improving the durability of the chemical discharge unit. [Effects of the Invention]

[0030] The drug solution discharge unit according to the present invention provides at least one of the following effects: it can suppress unauthorized changes in flow rate by the patient during drug administration; it can suppress the decrease in the click feel of the switching operation part over a long period of time; it can prevent unintended closure of the priming flow path before priming; it can improve the operability when pulling out the operation blocking member; and it can improve the durability of the drug solution discharge unit. [Brief explanation of the drawing]

[0031] [Figure 1] This is a schematic diagram showing the configuration of a drug administration device equipped with a drug solution discharge unit according to the embodiment. [Figure 2] This is a perspective view of the chemical solution discharge unit of the embodiment in its normal state. [Figure 3] This is a view from above in Figure 2. [Figure 4] This is a cross-sectional view along line AA in Figure 2. [Figure 5] This figure corresponds to the cross-section along line BB in Figure 2, showing the state when the chemical solution discharge unit of the embodiment is operated with the pressing operation member. [Figure 6] This is an enlarged perspective view showing the three-way stopcock with the switching operation part removed from Figure 2. [Figure 7] Figure 6 is an exploded perspective view. [Figure 8] Figure 2 shows the state in which an operating tool is inserted into the switching operation section and the switching operation section is operated. [Figure 9] Figure 2 is a perspective view of the chemical solution discharge unit, with the first housing omitted. [Figure 10] This is an enlarged perspective view taken in the direction of arrow C in Figure 2. [Figure 11] This is a perspective view showing the switch and operating blocker removed from Figure 10. [Figure 12] This diagram shows the chemical solution discharge unit of the embodiment, corresponding to the cross-section along line DD in Figure 9. [Figure 13] Figure 11 is an exploded perspective view. [Figure 14] This is an enlarged view of section H in Figure 13. [Figure 15] (a) is a diagram corresponding to Figure 12 showing the state in which the operation blocking member has been pulled out to the intermediate engagement position in the drug solution discharge unit of the embodiment, and (b) is an enlarged view of part E in (a). [Figure 16] (a) is a diagram corresponding to the FF line cross-section in Figure 9 showing the chemical solution discharge unit of the embodiment with the switch fully pressed down, (b) is a diagram corresponding to Figure 12 in the state of (a), and (c) is an enlarged view of section G in (b). [Figure 17] This figure shows the state after the operation-blocking member has been further extended, as shown in Figure 16(b). [Figure 18] (a) is a diagram showing the state in Figure 12 where the operation blocking member is tilted to its maximum extent in the direction of arrow α, and (b) is an enlarged view of part I in (a). [Figure 19] (a) is a diagram showing the comparative example of the chemical discharge unit with the operation blocking member tilted to its maximum extent in the direction of arrow β, and (b) is an enlarged view of section J in (a). [Figure 20]This is an enlarged view of the front portion of Figure 9, with some parts omitted, as seen from above. [Figure 21] Figure 20 is a diagram in which some of the flow paths are omitted. [Figure 22] This is a perspective view showing the outer connector component from Figure 20. [Figure 23] Figure 4 is a perspective view including the KK line cross-section. [Modes for carrying out the invention]

[0032] Hereinafter, an example of an embodiment of the chemical solution discharge unit according to the present invention will be described in detail with reference to the drawings. The embodiment described below is merely an example, and the present invention is not limited to the embodiments described below. Furthermore, it is intended from the outset that the components of the multiple embodiments and modified examples described below can be selectively combined.

[0033] Figure 1 is a schematic diagram showing the configuration of a drug dispensing device 1 equipped with a drug dispensing unit 20 according to an embodiment. Figure 2 is a perspective view of the drug dispensing unit 20 in its normal state, i.e., before priming. Figure 3 is a view of Figure 2 from above. Figure 4 is a cross-sectional view taken along line AA in Figure 2. Figure 5 is a diagram corresponding to the cross-sectional view taken along line BB in Figure 2, showing the drug dispensing unit 20 in a state where it has been operated by the push button 23, which is a pressing operation member.

[0034] As shown in Figures 1 to 4, the drug administration device 1, including the drug dispensing unit 20, is configured to include a main channel 2 having an external channel and a sub-channel 21 provided inside the drug dispensing unit 20 and connected to the main channel 2. A main reservoir 3 for storing drug solution is connected to one end of the main channel 2, and a terminal connector 4 is connected to the other end of the main channel 2.

[0035] The main reservoir 3 delivers the internal drug solution to the main channel 2. The terminal connector 4 connects to an indwelling needle or similar device that has been percutaneously inserted into the patient's blood vessel or other location.

[0036] The drug solution discharge unit 20 rapidly discharges the drug solution stored in the internal sub-reservoir 22 into the main channel 2 at the patient's own discretion when the patient desires rapid administration of the drug solution.

[0037] The chemical solution discharge unit 20 will be described in detail below with reference to Figures 2 to 5. The chemical solution discharge unit 20 includes a housing 24, an inlet passage 25 (Figure 1) and an outlet passage 26 (Figure 1) provided inside the housing 24, and a sub-reservoir 22 connected between the inlet passage 25 and the outlet passage 26. The inlet passage 25 and the outlet passage 26 are formed from elastically deformable tubes or the like. Hereinafter, with respect to the chemical solution discharge unit 20, the side on which the push button 23 is provided will be described as the rear side, the side opposite the push button 23 will be described as the front side, the side on which the switch 50 (described later) is provided will be described as the upper side, and the direction in which the switch 50 is pushed into the housing 24 will be described as the lower side. Also, the side on which the operation blocking member 80 (described later) is provided will be described as the left side, and the side opposite the operation blocking member 80 will be described as the right side. The front-rear direction, the up-down direction, and the left-right direction are orthogonal to each other.

[0038] The housing 24 is a substantially bottomed cylindrical shape and is composed of a first housing 30, a second housing 31, and a holder 32. The first housing 30 and the second housing 31 are semi-cylindrical bodies provided in approximately half the circumferential direction. When the first housing 30 and the second housing 31 are joined together, a cylindrical body with openings at both ends is formed. The holder 32 is attached between the first housing 30 and the second housing 31 so as to cover the opening at the front end of the cylindrical body. The opening at the rear end of the cylindrical body is closed by a push button 23. The cross-sectional shape of the housing 24 when cut by a plane perpendicular to the axial direction is a substantially elliptical shape with the vertical direction being the major axis and the horizontal direction being the minor axis. A sub-reservoir 22 (Figure 4) is housed inside the housing 24.

[0039] As shown in Figure 4, one end of the inflow channel 25 is connected to an inlet port 40 that opens at the front end of the housing 24, and one end of the discharge channel 26 is connected to an outlet port 41 that opens at the front end of the housing 24. The downstream portion of the inflow channel 25, the sub-reservoir 22, and the upstream portion of the discharge channel 26 form a sub-channel 21. A restricting channel 42 and a priming channel 43 are provided in parallel in the downstream portion of the inflow channel 25. The priming channel 43 has a larger channel cross-section than the restricting channel 42 which is connected in parallel. The priming channel 43 is opened and closed by the movement of a shut-off valve 51 (Figure 13) provided on a switch 50, which will be described later. That is, the priming channel 43 is closed when the priming channel 43 is elastically compressed by the shut-off valve 51, and the closed portion of the priming channel 43 is opened when the shut-off valve 51 moves away from the priming channel 43. When the priming channel 43 is closed, the chemical solution is sent to the sub-reservoir 22 in small amounts through the restricting channel 42. When the priming channel 43 is open, it becomes possible to rapidly send a large amount of chemical solution from the main channel 2 to the sub-reservoir 22 through the priming channel 43.

[0040] Furthermore, an on-off valve 44 (Figure 9) is provided in the upstream portion of the discharge passage 26, which uses a spring to press the valve body toward the discharge passage. The discharge passage 26 is switched open and closed by the operation of the on-off valve 44. Before the push button 23, described later, is pressed, the discharge passage 26 is elastically compressed by the valve body due to the biasing force of the spring and closed. When the push button 23 is pressed inward into the housing 24, the valve body is pushed away from the discharge passage 26 by a push-up piece (not shown) extending from the push button 23, and the closed portion of the discharge passage 26 opens.

[0041] The main connecting channel 45, which constitutes the main channel 2, is connected to the inlet port 40 side of the inflow channel 25 and the outlet port 41 side of the discharge channel 26. A flow rate switching mechanism 60 is connected in parallel to the main connecting channel 45. The flow rate switching mechanism 60 has a branch channel 61 (Figure 1) connected to the connection part of the downstream portion of the main connecting channel 45 and the inflow channel 25, a three-way stopcock 70 (Figures 1 and 6) connected to the downstream end of the branch channel 61, and a first channel 63 (Figure 9) and a second channel 64 (Figure 9) that can be connected to the three-way stopcock 70 and have different flow rates due to their different cross-sectional areas.

[0042] The three-way stopcock 70 is switched by a switching operation unit 71 (Figure 2), which is exposed at the front end of the housing 24 and will be described later. Switching the three-way stopcock 70 switches between a state in which one or both of the first and second flow paths 63 and 64 are connected in series with the branch flow path 61, and a state in which neither of the first and second flow paths 63 and 64 are connected with the branch flow path 61. As a result, the flow rate switching mechanism 60 is housed in the housing 24 and can switch the flow rate of the main flow path 2.

[0043] Furthermore, the drug dispensing unit 20 is equipped with a push button 23 as an operating member, enabling rapid administration of the drug by the patient's own operation. Specifically, the push button 23 is a bottomed cylindrical shape with a substantially elliptical cross-section and is mounted in the housing 24 so as to be movable along the axial direction. Inside the housing 24 are a plunger 65 (Figure 4) that presses against the sub-reservoir 22 and a biasing member provided between the push button 23 and the plunger 65. The biasing member is, for example, a coiled spring. The bottom of the plunger 65 is connected to the bottom of the diaphragm that forms the sub-reservoir 22. The diaphragm is a bottomed cylindrical shape, with the open end of the cylindrical part connected to the base part, and is expandable and contractible in the axial direction. The downstream end of the inflow channel 25 and the upstream end of the discharge channel 26 are connected to the base part. When the push button 23 is pressed inward toward the housing 24, the pressing force of the push button 23 is transmitted to the diaphragm of the sub-reservoir 22 via the biasing member and plunger 65, compressing the sub-reservoir 22. As a result, the drug solution stored inside the sub-reservoir 22 is discharged into the discharge channel 26. Also, the movement of the push button 23 opens the on / off valve 44, that is, the closed part of the discharge channel 26 opens. Therefore, when the patient presses the push button 23, the drug solution is rapidly discharged from the drug solution discharge unit 20, enabling rapid self-administration. Thus, the drug solution discharge unit 20 discharges the drug solution in the sub-reservoir 22 into the discharge channel 26 when the push button 23 is operated.

[0044] Switch 50 is used to depress after the rapid supply of the chemical solution to the sub-reservoir 22 through the priming channel 43 has finished and the internal channel is filled with the chemical solution. Depressing switch 50 closes the priming channel 43 with the shut-off valve 51. To prevent unintended depressing of switch 50, an operation blocking member 80, described later, is retractably engaged with switch 50.

[0045] The switching operation unit 71 of the flow rate switching mechanism 60 will be explained using Figures 2, 3, and 6 to 8. Figure 6 is an enlarged perspective view showing the three-way stopcock 70 with the switching operation unit 71 removed from Figure 2. Figure 7 is an exploded perspective view of Figure 6. Figure 8 shows the state in Figure 2 where the operating tool 27 is inserted into the switching operation unit 71 to operate the switching operation unit 71.

[0046] As shown in Figure 6, the three-way stopcock 70 is constructed by housing an operating member 70a having a switching operation unit 71 within a holder 32. The holder 32 includes two plate portions 33 and 34, a connecting cylinder (not shown) connecting the two plate portions 33 and 34, and an outer cylinder 35 protruding from one side of one of the plate portions 34. An inner column 72, which serves as a valve body and is integrally provided with the switching operation unit 71, is rotatably inserted into a cylindrical hole 36 inside the outer cylinder 35. The inner column 72 is in conjunction with the switching operation unit 71 and has a T-shaped flow path inside.

[0047] The outer cylinder 35 has three flow paths that can be connected to the three flow path ends of the T-shaped flow path of the inner column 72. The outer cylinder 35 is exposed on the outer surface of the housing 24 and is attached to the bottom plate portions 24a and 24b that constitute the front ends of the first housing 30 and the second housing 31 by sandwiching them between two plate portions 33 and 34. By rotating the switching operation unit 71 and the inner column 72 relative to the outer cylinder 35, the connection state between the flow path ends of the inner column 72 and the three flow paths of the outer cylinder 35 is switched, and the flow rate of the flow rate switching mechanism 60 is switched.

[0048] Furthermore, on the outer surface of the holder 32, a substantially annular first step portion 37 is formed inside the opening end of the hole 36, and a substantially annular second step portion 38 is formed inward from the first step portion 37, with a slightly smaller inner diameter. The first step portion 37 is capable of engaging with the rotating side projection 73 of the switching operation portion 71, which will be described later. The second step portion 38 is capable of engaging with the stepped surface between the disc portion of the switching operation portion 71 and the inner column 72. Furthermore, the first step portion 37 has multiple peaks 37a and multiple valleys 37b formed alternately one at a time in the circumferential direction. The multiple peaks 37a correspond to the fixed side projections.

[0049] The switching operation section 71 has a triangular rotating projection 73 formed on a portion of its outer circumferential surface in the circumferential direction. The outer surface of the switching operation section 71 has a recess 74 with a T-shaped cross-section, where the outer end opening is I-shaped at the upper end of the T-shape. The T-shaped locking portion 28 (Figure 9) of the operating tool 27 can be engaged with the recess 74, as shown in Figure 8, which will be described later.

[0050] The operating member 70a is assembled to the holder 32 with the inner column 72 inserted into the hole 36 of the holder 32. At this time, the stepped surface between the disc portion of the switching operation unit 71 and the inner column 72 engages with the second step portion 38, and the rotating side projection 73 engages with the first step portion 37. In this state, the switching operation unit 71 is positioned inside the hole 36 formed on the outer surface of the holder 32 and is exposed to the outside so as to be operable. Furthermore, an inner annular projection 75 is formed around the entire circumference of the outer circumferential surface of the tip of the inner column 72, and the operating member 70a is prevented from falling out of the holder 32 by the inner annular projection 75 overcoming and engaging with an outer annular projection (not shown) formed on the inner circumferential surface of the inner part of the hole 36. Furthermore, the outer circumferential surface of the switching operation unit 71 is configured so as not to protrude outside the opening end of the hole 36 of the holder 32. This makes it difficult for the patient to easily touch and operate the switching control unit 71 exposed on the outside of the housing 24. Therefore, unauthorized changes in the flow rate by the patient during drug administration can be suppressed.

[0051] Furthermore, as shown in Figure 8, the recess 74 (Figure 6) of the switching operation unit 71 is rotatable by inserting the locking portion 28 (Figure 9) of the operating tool 27 into it. Rotation of the switching operation unit 71 rotates the inner column 72, switching the flow rate of the flow rate switching mechanism 60. Normally, the operating tool 27 is attached to the housing 24 by locking a locking portion 29 provided on one side of the housing 24 into a locking hole formed in the housing 24.

[0052] Since the switching operation unit 71 has a recess 74 into which the operating tool 27 can be inserted and rotated, the switching operation unit 71 is easier to manufacture and its rigidity can be increased, thereby improving reliability.

[0053] Furthermore, the switching operation unit 71 is operably exposed to the outside of the housing 24 and rotatably positioned on the outer surface of the holder 32. Multiple ridges 37a are formed on the outer surface of the holder 32 at positions along the rotation direction of the switching operation unit 71, and the rotating side projection 73 protruding from the outer circumferential surface of the switching operation unit 71 can rotate while riding on the ridges 37a. As a result, a click sensation during operation can be obtained without placing a large load on the rotating side projection 73 of the switching operation unit 71, and thus the decrease in the click sensation of the switching operation unit 71 can be suppressed over a long period of time.

[0054] Furthermore, in the operating member 70a, the stepped surface on the inner column 72 side of the rotating projection 73 engages with the second step 38 of the hole 36. Therefore, the rotating projection 73 alone does not need to support the weight of the operating member 70a that extends from the operating member 70a to the inside of the housing 24. This reduces the load on the rotating projection 73, thereby further suppressing the reduction in click sensation.

[0055] In this example, a T-shaped recess 74 is formed in the switching operation unit 71, and the T-shaped locking portion 28 of the operating tool 27 can be engaged with the recess 74. However, the recess may be a polygon other than a T-shape, such as a hexagon, and the operating tool may have a locking portion that protrudes in a shape matching the recess and can be engaged with the recess. Alternatively, the switching operation unit may have an I-shaped, cross-shaped, hexagonal, or other polygonal projection on its exposed front end surface, and the operating tool may have a recess that is recessed in a shape matching the projection and can be engaged with the projection. Even in this case, the outer circumferential surface of the projection of the switching operation unit is configured not to protrude beyond the opening end of the hole 36 of the holder 32.

[0056] Next, using Figures 9 to 18, the structure of the switch 50 and the operating prevention member 80 will be explained to prevent unintended closure of the priming channel 43 and to improve operability when pulling out the operating prevention member 80. First, using Figures 9 to 13, the engagement structure of the switch 50 and the operating prevention member 80 will be explained.

[0057] Figure 9 is a perspective view of the chemical discharge unit 20 in Figure 2, with the first housing 30 omitted. Figure 10 is an enlarged perspective view in the direction of arrow C in Figure 2. Figure 11 is a perspective view of Figure 10 with the switch 50 and operation blocking member 80 removed. Figure 12 is a diagram of the chemical discharge unit 20 corresponding to the cross-section along line DD in Figure 9. Figure 13 is an exploded perspective view of Figure 11.

[0058] As shown in Figures 9 and 10, the switch 50 is inserted from top to bottom through a roughly rectangular first hole 24c formed vertically in the housing 24. A portion of the switch 50 protrudes upward from the housing 24. A roughly rectangular second hole 24d is also formed in the housing 24 in the left-right direction, and the second hole 24d communicates with the first hole 24c. A portion of the operating prevention member 80 is inserted into the housing 24 from left to right through the second hole 24d. In this state, as shown in Figure 11, a portion of the operating prevention member 80 is inserted into the insertion hole 52 formed in the switch 50.

[0059] Specifically, as shown in Figures 11 and 12, the switch 50 and the operation blocking member 80 constitute a closing mechanism 100 that closes the priming channel 43 when the switch 50 is pushed into the housing 24. The operation blocking member 80 prevents the push operation of the switch 50 and is assembled to the switch 50 so that it can be pulled out from the switch 50.

[0060] As shown in Figure 13, the switch 50 has a shut-off valve 51 inserted into the housing 24 and an operating end 53 integrally provided on the upper side, which is rearward in the pushing direction from the shut-off valve 51. The operating end 53 has a roughly box shape with a peripheral wall connected to the right side of the side wall 54, and an insertion hole 52 is formed inside the side wall 54. The upper end of the operating end 53 protrudes outward from the housing 24 and has a roughly cross shape with protrusions protruding from both edges in the front-rear direction. The upper surface of the operating end 53 is curved in a circular arc shape in cross-section, and as shown in Figures 16 and 17 described later, when the switch 50 is fully pushed into the housing 24, the upper surface of the operating end 53 forms a curved surface that is continuous with the outer circumferential surface of the housing.

[0061] The shut-off valve 51 is a long, plate-like shape with a roughly rectangular cross-section, and a vertically elongated projection is formed on one side in the thickness direction, protruding below the lower end of the operating end 53, in order to deform the priming passage 43.

[0062] The insertion hole 52 of the operating end 53 has two switch-side protrusions 55 that project inward from the insertion hole 52 at the upper and lower intermediate portions of both the front and rear edges. At the lower end of the insertion hole 52, a first region A1 is formed where the distance in the front-rear direction is larger below the switch-side protrusions 55, a second region A2 is formed above the first region A1 where the distance in the front-rear direction is smaller corresponding to the switch-side protrusions 55, and a third region A3 is formed above the second region A2 where the distance in the front-rear direction is larger than that of the first region A1. In the state shown in Figures 10 to 12, the operation blocking member 80 is inserted into the first region A1.

[0063] As shown in Figure 13, the operation blocking member 80 has a substantially rectangular cross-section and is elongated in the left-right direction, and includes two insertion portions 81 that are inserted into the switch 50, and a pull-out operation portion 84 integrally provided at the left end of the two insertion portions 81. The pull-out operation portion 84 has a cylindrical portion 85 connected to the left side, which is one side in the longitudinal direction of each insertion portion 81. The cylindrical portion 85 has a substantially rectangular cross-section and is open at its right end. One end of the cylindrical portion 85, the right end, is pressed against the outer circumferential surface of the housing 24. The other end of the cylindrical portion 85, the left end, is closed by an outer wall 86. Locking grooves 87 extending in the left-right direction are formed in the middle of the front and rear ends of the side walls of each side wall at both ends of the cylindrical portion 85. Each locking groove 87 is capable of engaging and holding an external flow path that extends along the front-rear direction to the outside of the housing.

[0064] Each insertion portion 81 of the operation blocking member 80 has a groove 82 that penetrates vertically through the front-to-back outer surface of the longitudinal middle portion. The switch side projection 55 formed in the insertion hole 52 of the switch 50 can pass through the groove 82 in the vertical direction.

[0065] Two guide insertion portions 88 are formed at both the front and rear ends of the lower end of the operating prevention member 80, extending toward the inside of the housing 24. The two guide insertion portions 88 are inserted into two holes (not shown) formed on the outer surface of the housing 24, thereby guiding the movement of the operating prevention member 80 in the withdrawal direction and the opposite direction.

[0066] Figure 14 is an enlarged view of section H in Figure 13. As shown in Figures 13 and 14, in each insertion section 81, a V-shaped pull-out side projection 83 is formed on the upper surface of the portion adjacent to the left side of the groove 82, which is the side of the operation blocking member 80 that is being pulled out. When the operation blocking member 80 is pulled out from the insertion hole 52 of the switch 50, the switch side projection 55 can ride over this pull-out side projection 83. The pull-out side projection 83 corresponds to a guide that guides the user through touch to indicate that the switch 50 is ready to be pressed.

[0067] Figures 12 and 15-17 illustrate the operation when the priming channel 43 is closed by pressing down the switch 50. Before the push button 23 is pressed, the chemical solution is sent to the sub-reservoir 22 through the priming channel 43, and then the priming channel 43 is closed. At this time, in the initial state shown in Figure 12, the lower end of the switch-side projection 55 of the switch 50 contacts the upper surface of the insertion portion 81 of the operation blocking member 80, preventing the switch 50 from being pressed. In this state, the operation blocking member 80 is inserted into the insertion hole 52, and the groove 82 of the operation blocking member 80 and the switch-side projection 55 are not facing each other in the direction from top to bottom, which is the direction of pressing. In this state, the operating end 53 of the switch 50 engages with the operation blocking member 80, preventing the switch 50 from being pushed into the housing 24. This prevents the user from accidentally operating the switch 50.

[0068] Figure 15(a) is a diagram corresponding to Figure 12, showing the state in the liquid dispensing unit 20 where the operation blocking member 80 has been pulled out to the intermediate engagement position, and Figure 15(b) is an enlarged view of part E in Figure 15(a). When the operation blocking member 80 is pulled outward from the state in Figure 12, the switch-side projection 55 overcomes the pull-out side projection 83, and as shown in Figure 15, the switch-side projection 55 faces the groove 82 of the operation blocking member 80 in the vertical direction. In this state, the switch 50 can be pushed in downward. At this time, the projection 81a (Figure 14) that protrudes on both the front and rear sides in the front-rear direction from the tip side, i.e., the right end side, of the side wall portion 54 corresponding to the front and rear edges of the first region A1 of the insertion hole 52 of the switch 50 shown in Figure 10 abuts against the lower end of the side wall portion 54, which is the front and rear edge side of the groove 82 of the operation blocking member 80, i.e., the right end side, and prevents the switch 50 from being pulled out any further.

[0069] Figure 16(a) is a diagram corresponding to the FF line cross-section in Figure 9, showing the state in which the switch 50 is fully pushed in in the chemical discharge unit 20, Figure 16(b) is a diagram corresponding to Figure 12 in the state of Figure 16(a), and Figure 16(c) is an enlarged view of section G in Figure 16(b). When the switch 50 is fully pushed into the housing 24 from the state of Figure 15, each insertion portion 81 of the operation blocking member 80 enters the third region A3 in the insertion hole 52 of the switch 50. In this state, the front-to-back length of the portion of the insertion hole 52 where the insertion portions 81 are located is wider than in the case of the first region A1, and in this portion, the operation blocking member 80 can be further withdrawn. Also in this state, the priming passage 43 is pressed by the shut-off valve 51 provided on the switch 50 toward the inner wall 24e provided on the inside of the housing 24, and is closed by being elastically crushed between the inner wall 24e and the shut-off valve 51. In this state, the locking portion 51a provided at the tip of the shut-off valve 51 engages with the tip of the locking portion 24f which protrudes from the inner wall 24e and is bent downward, thereby maintaining the closed state of the priming passage 43.

[0070] Figure 17 shows the operating prevention member 80 further extended from the state in Figure 16(b). As shown in Figure 17 from the state in Figure 16, the operating prevention member 80 can be completely removed from the switch 50 and housing 24 by pulling it out in the direction of the white arrow.

[0071] Furthermore, in this example configuration, as shown in Figure 18, unintended closure of the priming channel 43 is prevented by restricting the position of the groove 82 of the operation blocking member 80. Figure 18(a) shows the state in Figure 12 where the operation blocking member 80 is tilted to its maximum extent in the direction of arrow α, and Figure 18(b) is an enlarged view of part I in Figure 18(a).

[0072] In the state shown in Figure 12, the operation blocking member 80 can be tilted in the left-right direction along the withdrawal direction, as shown in Figure 18, when a force is applied from above to the protruding end of the cylindrical portion 85. Therefore, if a load in the tilting direction (direction of arrow α in Figure 18) is accidentally applied to the operation blocking member 80 before priming, such as when transporting the chemical discharge unit 20, the operation blocking member 80 will tilt with respect to the withdrawal direction, and the groove 82 of the operation blocking member 80 will approach the switch-side projection 55 of the switch 50 and face it in the vertical direction, which may allow the switch 50 to be pushed in. As a result, if a load in the pushing direction is unintentionally applied to the switch 50, the switch 50 may be pushed in, and the priming passage 43 may be unintentionally closed before priming.

[0073] In this example, to prevent such inconveniences, as shown in Figure 18, when the switch 50 is tilted to its maximum extent in the pulling direction before the operation blocking member 80 is pulled out, the left end of the groove 82 of the operation blocking member 80 (the end indicated by Q in Figure 18), which is the front end in the pulling direction, is located to the right of the position facing the switch side projection 55 (position P in Figure 18), which is the rear end in the pulling direction. This prevents unintended closure of the priming channel 43 before priming, as will be described later.

[0074] Figure 19(a) shows the comparative example of the chemical discharge unit 20a with the operation blocking member 80a tilted to its maximum extent in the direction of arrow β, and Figure 19(b) is an enlarged view of section J in Figure 19(a). In the comparative example, the groove 82 of the operation blocking member 80a is located on the base side of the insertion portion 81 (left side in Figure 19(a)) than in the embodiment. As shown in Figure 19(a), when the switch 50 is tilted to its maximum extent with respect to the withdrawal direction before the operation blocking member 80a is withdrawn, the front end Q of the groove 82 of the operation blocking member 80a is located opposite the switch side projection 55. In such a configuration, as described above, when a load in the pushing direction is unintentionally applied to the switch 50, the switch 50 may be pushed in, and the priming passage 43 may be unintentionally closed before priming.

[0075] On the other hand, according to the embodiment shown in Figure 18, even if a load in the tilting direction is mistakenly applied to the operation blocking member 80 before priming, causing the operation blocking member 80 to tilt relative to the pulling direction, the switch-side projection 55 and the groove 82 do not face the direction of pushing in the switch 50. As a result, the switch 50 cannot be pushed in, and thus unintended closure of the priming channel 43 can be prevented before priming.

[0076] Furthermore, as shown in Figures 14 and 15 above, the liquid discharge unit 20 in this example has a pull-out side projection 83 that serves as a guide to inform the user by touch when the switch 50 is ready to be pressed. This allows the user performing the pull-out operation of the operation blocking member 80 to easily determine when the switch 50 is ready to be pressed, thereby improving the operability when pulling out the operation blocking member 80. Thus, in this example, the operation blocking member 80 has a guide that informs the user by touch when the switch is ready to be pressed. Note that the guide is not limited to being present only on the operation blocking member, but can also be composed of components from both the operation blocking member and other members. In addition, in the configuration of this example, the user can determine when the switch 50 is ready to be pressed by touch, but this is not limited to this, and the user can determine when the switch is ready to be pressed by other senses, such as hearing. For example, a metal plate may be attached to the lower surface of the switch-side projection 55, and another metal plate may be attached to the upper surface of the operation-blocking member 80 on the rear side of the groove 82 in the pulling direction, so that the metallic sound when these metal plates come into contact can be used to determine whether the switch 50 is in a state where it can be pressed. In this case, the guide portion is composed of both the operation-blocking member and the switch.

[0077] Furthermore, the pull-out operation portion 84 of the operation-blocking member 80 includes an outer wall 86 that closes the other end of the cylindrical portion 85 opposite to the insertion portion 81. As a result, when the user pulls out the pull-out operation portion 84, the user can only grasp the outer surfaces of the two walls of the cylindrical portion 85, which are far apart from each other. This suppresses the tilt of the pull-out direction relative to the normal direction compared to when the user grasps a part of the outer circumferential direction of the outer end of the cylindrical portion which has an open outer end. Therefore, since the operation-blocking member 80 is prevented from being pulled out while tilted relative to the normal direction, excessive stress is not generated between the operation-blocking member 80 and the switch 50, and deformation of the components is prevented. Consequently, the durability of the components of the chemical discharge unit 20 can be improved.

[0078] Next, using Figures 20 to 23, a structure for preventing deformation of the housing 24 when closing the priming channel 43 will be explained. Figure 20 is an enlarged view from above of the front portion of Figure 9, with some parts omitted. Figure 21 is a view of Figure 20 with some of the channels omitted. Figure 22 is a perspective view showing the outer connector member 101 from Figure 20. Figure 23 is a perspective view including the KK line cross section of Figure 4. As described above, the priming channel 43 is pressed by the shut-off valve 51 provided on the switch 50 towards the inner wall 24e provided on the inside of the housing 24 when the switch 50 is pressed, and is closed by being elastically crushed between the inner wall 24e and the shut-off valve 51.

[0079] On the other hand, if there is a gap between the outer wall side of the housing 24 and the housing 24 on the inner wall 24e, deformation of the inner wall 24e, which is pressed by the switch 50, may occur with long-term use, so there is room for improvement in terms of improving the durability of the chemical discharge unit.

[0080] In this example configuration, to prevent such problems, as shown in Figures 20 and 21, a gap is filled inside the housing 24 in the direction perpendicular to the pressing direction of the switch 50, i.e., the left-right direction, on the side opposite the shut-off valve 51 which is the pressing part of the switch 50, so as to linearly connect the outer wall of the housing 24 and the priming passage 43. As a result, as shown by the dashed line γ in Figure 20, the outer wall of the housing 24 and the priming passage 43 are linearly connected without any gaps. For this purpose, an outer connector member 101, as shown in Figure 22, is provided inside the housing 24.

[0081] The outer connector member 101 has a configuration in which a discharge channel 26 with an outlet port 41 and a bracing portion 102 are connected by a plate portion 103. A groove 104 is provided in the plate portion 103, and a priming channel 43 can be locked into the groove 104. The bracing portion 102 has a vertical plate portion 105 that extends in the vertical direction, a connecting plate portion 106 connected to the vertical plate portion 105 so as to be perpendicular to the outer wall side of the housing 24 with respect to the position (position R in Figure 20) where the shut-off valve of the priming channel 43 is pressed, and an outer wall contact plate portion 107 connected to the outer wall side of the connecting plate portion 106. The outer wall contact plate portion 107 has a rhombic shape that widens in the center in the vertical direction when viewed from left to right. The outer wall contact plate portion 107 contacts the outer wall of the housing 24. As a result, as shown in Figures 20 and 23, in the direction perpendicular to the pushing direction of the switch 50, a gap is filled on the side of the priming channel 43 opposite the shut-off valve 51 of the switch 50, so as to linearly connect the outer wall of the housing 24 and the priming channel 43. As shown in Figure 20, the connecting plate portion 106 also has the function of wrapping around a part of the channel, such as the restricting channel 42.

[0082] This prevents deformation of the housing 24 when closing the priming channel 43, compared to when there is a gap between the outer wall of the housing 24 and the pressing position of the priming channel 43, thereby improving the durability of the chemical discharge unit 20. In this example, an outer connector member 101 is provided between the inner wall 24e and the outer wall of the housing 24 as a separate component from the housing 24, but the configuration is not limited to this. For example, any configuration that fills the gap on the opposite side of the shut-off valve 51 of the switch 50, so as to linearly connect the outer wall of the housing 24 and the priming channel 43, would suffice. For example, the outer wall and inner wall of the housing may be directly connected at a part of the housing, and the gap may be filled. [Explanation of Symbols]

[0083] 1 Drug dispensing device, 2 Main channel, 3 Main reservoir, 4 End connector, 20, 20a Drug discharge unit, 21 Sub channel, 22 Sub reservoir, 23 Push button, 24 Housing, 24a, 24b Bottom plate, 24c First hole, 24d Second hole, 24e Inner wall, 24f Locking part, 25 Inflow channel, 26 Discharge channel, 27 Operating tool, 28, 29 Locking parts, 30 First housing, 31 Second housing, 32 Holder, 33, 34 Plate part, 35 Outer cylinder, 36 Hole, 40 Inlet port, 41 Outlet port, 42 Restricting channel, 43 Priming channel, 45 Main connection channel, 50 Switch, 51 Shut-off valve, 51a Locking part, 52 Insertion hole, 53 Operating side end, 54 Side wall, 55 60 Switch side projection, 61 Flow switching mechanism, 63 First flow path, 64 Second flow path, 65 Plunger, 70 Three-way stopcock, 70a Operating member, 71 Switching operation part, 72 Inner column, 73 Rotating side projection, 74 Recess, 75 Inner annular projection, 80, 80a Operation blocking member, 81 Insertion part, 81a Projection, 82 Groove, 83 Pull-out side projection, 84 Pull-out operation part, 85 Cylinder part, 86 Outer wall, 87 Locking groove, 100 Closing mechanism, 101 Outer connector member, 102 Bracing part, 103 Plate part, 104 Groove, 105 Vertical direction plate part, 106 Connecting plate part, 107 Outer wall contact plate part.

Claims

1. A chemical solution discharge unit in which a reservoir is housed in a housing and the chemical solution in the reservoir is discharged into a discharge channel by operating an operating member, A flow rate switching mechanism housed in the aforementioned housing, the flow rate switching mechanism capable of switching the flow rate of the main flow path connected to the discharge flow path, The device includes a switching operation unit that is linked to the valve body of the flow rate switching mechanism and moves the valve body by operation to switch the flow rate of the flow rate switching mechanism, The switching operation unit is positioned within a hole formed in the outer surface of the housing and is exposed to the outside so as to be operable, and the outer circumferential surface of the switching operation unit is configured so as not to protrude beyond the opening end of the hole. A priming channel connected to the reservoir has a larger channel cross-section than the parallel-connected restricting channels, The device includes a closing mechanism that closes the priming channel by pushing the switch into the housing, Inside the housing, on the side of the priming channel opposite to the switch pressing portion in a direction perpendicular to the switch pressing direction, a gap is filled in such a way that the outer wall of the housing and the priming channel are connected in a straight line. Chemical solution discharge unit.

2. In the chemical solution discharge unit according to claim 1, The switching operation unit is a chemical discharge unit having a recess into which an operating tool can be inserted and rotated.

3. In the drug solution discharge unit according to Claim 1 or Claim 2, The switching operation unit rotates the valve body by rotational operation to switch the flow rate of the flow rate switching mechanism, and is operably exposed to the outside of the housing, and is rotatably arranged on the outer surface of the housing. Multiple fixed-side protrusions are formed on the outer surface of the housing along the rotation direction of the switching operation unit, and the rotating-side protrusions protruding from the outer circumferential surface of the switching operation unit are rotatable while riding on the fixed-side protrusions. Chemical solution discharge unit.

4. In the drug solution discharge unit according to any one of Claims 1 to 3, The switch is further equipped with an operation blocking member that prevents the push operation, The switch includes a shut-off valve for closing the priming passage and an operating end having an insertion hole, which is integrally provided on the rear side of the shut-off valve in the pushing direction. The aforementioned operation blocking member is assembled to the switch so as to be removable from the switch. When the operating prevention member is inserted into the insertion hole, and the groove formed in the operating prevention member and the switch-side projection protruding inward from the insertion hole are not facing each other in the pushing direction, the operating-side end engages with the operating prevention member, preventing the switch from being pushed into the housing. In the state before the operation blocking member is withdrawn, when the switch is tilted to its maximum extent with respect to the withdrawal direction, the front end of the groove in the withdrawal direction is located on the rear side in the withdrawal direction of the operation blocking member, relative to the position facing the switch side projection. Chemical solution discharge unit.

5. In the drug solution discharge unit according to any one of Claims 1 to 3, The switch is further equipped with an operation blocking member that prevents the push operation, The switch has a guide section that tactilely informs the user when the switch is ready to be pressed. Chemical solution discharge unit.

6. In the drug solution discharge unit according to any one of Claims 1 to 3, The switch is further equipped with an operation blocking member that prevents the push operation, The aforementioned operation blocking member is assembled to the switch so as to be removable from the switch. The aforementioned operation blocking member includes an insertion portion that is inserted into the switch and a withdrawal operation portion that is integrally provided with the insertion portion. The withdrawal operation section is connected to one side of the insertion section in the longitudinal direction and includes a cylindrical portion, one end of which is pressed against the outer circumferential surface of the housing, and an outer wall that closes the other end of the cylindrical portion. Chemical solution discharge unit.

7. A chemical solution discharge unit in which a reservoir is housed in a housing and the chemical solution in the reservoir is discharged into a discharge channel by operating an operating member, A priming channel connected to the reservoir has a larger channel cross-section than the parallel-connected restricting channels, The device includes a closing mechanism that closes the priming channel by pushing the switch into the housing, Inside the housing, on the side of the priming channel opposite to the switch pressing portion in a direction perpendicular to the switch pressing direction, a gap is filled in such a way that the outer wall of the housing and the priming channel are connected in a straight line. Chemical solution discharge unit.

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