Injection device

Abstract

The invention discloses an injection device which comprises a shell provided with a first limiting part; the radial wheel can be rotationally arranged in the shell in the first direction and is provided with a second limiting part; the clutch is provided with a third limiting part and a fourth limiting part and can be switched between a first axial position and a second axial position, the fourth limiting part is always matched with the second limiting part for limiting, and when the clutch is located at the first axial position, the third limiting part is matched with the first limiting part for limiting, so that the clutch and the shell are fixed; when the clutch is located at the second axial position, the third limiting part is separated from the first limiting part; the push rod and the radial wheel are limited in the circumferential direction, the push rod can axially move relative to the radial wheel, and the push rod axially moves synchronously when rotating in the circumferential direction. The clutch can be combined with or separated from the shell, and during combination, the push rod is indirectly limited, so that the push rod does not generate injection action; during separation, limiting of the shell to the clutch is relieved, and the push rod can conduct injection smoothly. The clutch transmission structure is simple, the number of parts is small, and transmission is simple and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of medical instruments, and more particularly to an injection device. Background Art

[0002] With the development of medical device technology, injection devices are widely used in the medical field.

[0003] The injection device is usually provided with a clutch mechanism, so that when the dosage of the injection device is adjusted, the injection mechanism maintains a constant position by switching the position of the clutch mechanism, thereby preventing an injection action.

[0004] However, in the related art, the structure of the clutch mechanism is usually complicated and has many parts, which makes it inconvenient to assemble the injection device.

[0005] Therefore, how to provide an injection device with a simpler clutch mechanism is a problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0006] In view of this, an object of the present invention is to provide an injection device, the clutch mechanism of which has a simple structure.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] An injection device, comprising:

[0009] The housing is provided with a first limiting portion;

[0010] A radial wheel is rotatably disposed in the housing along a first direction and is provided with a second limiting portion;

[0011] The clutch is provided with a third limiting part and a fourth limiting part, and can be switched between a first axial position and a second axial position, the fourth limiting part is always limited in cooperation with the second limiting part, when the clutch is in the first axial position, the third limiting part is limited in cooperation with the first limiting part, so that the clutch and the housing are relatively fixed, and when the clutch is in the second axial position, the third limiting part is disengaged from the first limiting part, so that the clutch and the housing can rotate relative to each other in the radial direction;

[0012] The push rod is circumferentially limited with the radial wheel and can move axially relative to the radial wheel. The push rod moves axially synchronously when it rotates circumferentially.

[0013] Optionally, it also includes:

[0014] A driving rod, axially connected to the clutch;

[0015] A button is axially connected to the driving rod and is pressably arranged on the housing, so that when the button is pressed, the driving rod drives the clutch to move from the first axial position to the second axial position.

[0016] Optionally, it also includes:

[0017] A sleeve is arranged in the housing, the sleeve is provided with a spring piece pawl, the clutch is provided with a first ratchet, and the spring piece pawl extends into a first tooth groove of the first ratchet;

[0018] A dynamic elastic member is connected between the sleeve and the housing and has a preset torsional preload force so that the sleeve always tends to rotate in a first direction relative to the housing, so that after the clutch is separated from the housing, the sleeve drives the clutch to rotate synchronously in the first direction.

[0019] Optionally, it also includes:

[0020] A pawl device is fixedly connected to the driving rod, and is provided with a pawl side wall located on the outside of the spring pawl, and the wall thickness of the pawl side wall gradually increases from one side to the other side along the circumferential direction. When the clutch is in the first axial position and the driving rod rotates along the first direction, the pawl side wall squeezes the spring pawl to disengage from the first tooth groove, so that the pawl device drives the sleeve to rotate synchronously along the first direction.

[0021] Optionally, the end of the driving rod close to the injection end is provided with at least two end clamps distributed along the same circumference, the outer periphery of the end clamps is provided with a first protrusion and a second protrusion spaced apart in the axial direction, and the outer periphery of the driving rod is further provided with a third protrusion spaced apart from the second protrusion in the axial direction;

[0022] The clutch is provided with a radially inwardly convex inner flange, and the inner flange and the spring pawl are respectively arranged in the gap between the first protrusion and the second protrusion, so that the clutch, the sleeve and the drive rod are axially limitedly connected;

[0023] The pawl device is clamped in the gap between the second protrusion and the third protrusion, and one of the pawl device and the driving rod is provided with a limiting notch, and the other is provided with a limiting rib that cooperates with the limiting notch to limit the position.

[0024] Optionally, the clamping claw device and the driving rod are an integrally processed structure or a split structure.

[0025] Optionally, the shell is provided with a rotatable knob, one of the drive rod and the knob is provided with a protruding tooth, and the other is provided with a tooth groove, when the button is not pressed, the protruding tooth cooperates with the tooth groove, and when the button is pressed, the protruding tooth disengages from the tooth groove.

[0026] Optionally, a return spring is provided between the button and the housing, and the return spring is used to provide an elastic force to the button to move it away from the injection end;

[0027] and / or,

[0028] The sleeve is axially connected to the driving rod, and the power elastic member also has a preset axial tensile force, so that when the button is released, the power elastic member drives the sleeve to drive the driving rod to reset.

[0029] Optionally, the first limiting portion is an inner edge annular tooth provided on the inner wall of the housing; the third limiting portion is a first outer spline provided on the outer peripheral portion of the clutch;

[0030] And / or, the second limiting portion is a second outer spline provided on the outer periphery of the radial wheel, and the fourth limiting portion is an inner spline provided on the inner periphery of the clutch, and the inner spline is slidingly matched with the second outer spline.

[0031] Optionally, a cam is provided in the housing, the cam is provided with an internal thread, and the outer periphery of the push rod is provided with two rows of discontinuous spiral teeth distributed along the axial direction to form a discontinuous external thread, and the external thread is threadedly connected with the internal thread;

[0032] A limiting guide groove extending in the axial direction is provided between the two rows of spiral teeth, and the radial wheel is provided with a radial inner protrusion for slidingly cooperating with the limiting guide groove; and / or,

[0033] The cam is provided with a second ratchet tooth, and the radial wheel is provided with an elastic arm, the elastic arm extending into the second tooth groove of the second ratchet tooth, so that the radial wheel can rotate relative to the cam (13) along a first direction.

[0034] The injection device provided by the present invention, when the injection device is not injecting, the clutch is located at the first axial position. At this time, the third limiting portion of the clutch cooperates with the first limiting portion of the shell to limit, so that the clutch and the shell are relatively fixed, and the clutch is limited by the shell to keep the circumferential position of the clutch fixed. Since the fourth limiting portion is always limited by the second limiting portion, that is, the clutch and the radial wheel are always combined, when the clutch is in the first axial position, the radial wheel cannot rotate under the limitation of the clutch and the shell, so that the push rod cannot rotate. Since the rotation and axial movement of the push rod are synchronous, that is, the push rod rotates and moves axially at the same time, when the push rod cannot rotate, the push rod cannot move axially, so that no injection action is generated. That is, when the injection device is adjusted to increase or decrease the injection dose during non-injection, no injection activity is generated under the limitation of the clutch and the shell.

[0035] When injection is required, the clutch is switched to the second axial position. At this time, the third limiting portion of the clutch is disengaged from the first limiting portion of the shell, thereby releasing the limiting effect of the shell on the clutch, allowing the clutch to move circumferentially, thereby allowing the radial wheel to move circumferentially. In this way, the radial wheel can avoid interfering with the circumferential movement of the push rod, thereby allowing the push rod to move axially smoothly. When the push rod is rotated in the first direction, the push rod synchronously moves toward the injection end of the shell to achieve injection.

[0036] It can be seen that the injection device switches the clutch between the first axial position and the second axial position to make the clutch engage or disengage with the housing. When the clutch engages with the housing, the housing is used to limit the clutch, thereby indirectly limiting the push rod, so that the push rod will not produce an injection action when the push rod is not injecting. When the clutch is separated from the housing, the limiting effect of the housing on the clutch is released, so that the push rod can be injected smoothly. At the same time, the fourth limiting part is always used to limit with the second limiting part, so that the clutch always maintains a synchronous circumferential position with the radial wheel, that is, the clutch and the push rod are indirectly always connected in circumferential motion, so that the state of the push rod can be ensured by limiting or releasing the clutch by the housing. The clutch transmission structure is simple, with few parts and components, and the transmission is simple and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0038] Figure 1 A partial exploded view of an injection device provided by a specific embodiment of the present invention (wherein the housing is a perspective view);

[0039] Figure 2 It is a schematic diagram of the structure of the clutch and the radial wheel;

[0040] Figure 3 It is a schematic diagram of the structure when the clutch and the housing are not combined;

[0041] Figure 4 is a cross-sectional view of the injection device;

[0042] Figure 5 is a schematic diagram of the structure of the driving rod;

[0043] Figure 6 is a schematic diagram of the structure of the sleeve;

[0044] Figure 7 is a schematic diagram of the structure of the clutch;

[0045] Figure 8 It is a structural schematic diagram of the claw device;

[0046] Fig. 9 It is a schematic diagram of the structure after the drive rod, clutch, sleeve and claw device are assembled;

[0047] Fig.10 for Fig. 9 A structural diagram from another perspective;

[0048] Fig.11 It is a schematic diagram of the matching relationship between the drive rod, the clutch, the sleeve and the claw device after assembly;

[0049] Fig.12 It is a schematic diagram of a structure in which the driving rod and the clamping claw are integrally processed;

[0050] Fig.13 It is a schematic diagram of the connection structure between the driving rod and the button;

[0051] Fig.14 It is a schematic diagram of the connection structure between the driving rod and the knob;

[0052] Fig.15 It is a schematic diagram of the structure of the radial wheel;

[0053] Fig.16 is a schematic diagram of the structure of the push rod;

[0054] Fig.17 It is a schematic diagram of the structure after the push rod and the radial wheel cooperate;

[0055] Fig.18 It is a structural diagram of the cam;

[0056] Fig.19 It is a schematic diagram of the structure after the cam and radial wheel cooperate.

[0057] Reference numerals:

[0058] 1-housing; 11-first limiting part; 2-radial wheel; 21-second limiting part; 22-radial inner convex block; 23-elastic arm; 3-clutch; 31-third limiting part; 32-fourth limiting part; 33-first ratchet; 34-inner flange; 4-push rod; 41-helical tooth; 42-limiting guide groove; 5-driving rod; 51-end clamping claw; 52-first protrusion; 53-second protrusion; 54-third Raised portion; 55-limiting rib; 56-raised tooth; 57-fourth raised portion; 6-button; 61-end convex circle; 7-sleeve; 71-spring claw; 72-first slot; 8-power elastic member; 9-claw device; 91-claw side wall; 92-limiting notch; 10-knob; 101-tooth groove; 12-reset spring; 13-cam; 131-internal thread; 132-second ratchet; 14-shell cover. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] The core of the present invention is to provide an injection device, the clutch mechanism of which has a simple structure and fewer parts, making it convenient to assemble the injection device.

[0061] Please refer to Figure 1 , Figure 2 and Figure 3 The embodiment of the present invention provides an injection device, comprising a housing 1, a radial wheel 2, a clutch 3 and a push rod 4 (such as Figure 4 As shown in the figure, the housing 1 is provided with a first limiting portion 11; the radial wheel 2 is rotatably arranged in the housing 1 along the first direction, and the radial wheel 2 is provided with a second limiting portion 21; the clutch 3 is provided with a third limiting portion 31 and a fourth limiting portion 32, and the clutch 3 can be switched between the first axial position and the second axial position, and the fourth limiting portion 32 is always limited in cooperation with the second limiting portion 21. When the clutch 3 is in the first axial position, the third limiting portion 31 is limited in cooperation with the first limiting portion 11, so that the clutch 3 and the housing 1 are relatively fixed. When the clutch 3 is in the second axial position, the third limiting portion 31 is disengaged from the first limiting portion 11, so that the clutch 3 and the housing 1 can rotate radially relative to each other; the push rod 4 is circumferentially limited with the radial wheel 2, and can move axially relative to the radial wheel 2. The push rod 4 moves axially synchronously when rotating circumferentially.

[0062] That is to say, when the push rod 4 moves, it rotates circumferentially and moves axially at the same time, and the axial movement and circumferential rotation of the push rod 4 are linked and performed synchronously. It can be understood that when the push rod 4 moves toward the injection end of the injection device, injection is achieved, and when the push rod 4 moves away from the injection end, the push rod 4 is reset. For example, in some embodiments, when the push rod 4 rotates in a first direction, it moves synchronously toward the injection end of the housing 1 to achieve injection, that is, the rotation of the push rod 4 in the first direction is defined as the injection direction.

[0063] It can be understood that when the injection device is not injecting, the clutch 3 is located at the first axial position. At this time, the third limiting portion 31 of the clutch 3 cooperates with the first limiting portion 11 of the housing 1 to limit, so that the clutch 3 and the housing 1 are relatively fixed. The clutch 3 is limited by the housing 1 to keep the circumferential position of the clutch 3 fixed. Since the fourth limiting portion 32 is always limited by the second limiting portion 21, that is, the clutch 3 is always combined with the radial wheel 2. Therefore, when the clutch 3 is in the first axial position, the radial wheel 2 cannot rotate under the limitation of the clutch 3 and the housing 1, so that the push rod 4 cannot rotate. Since the rotation and axial movement of the push rod 4 are synchronous, that is, the push rod 4 rotates and moves axially at the same time, when the push rod 4 cannot rotate, the push rod 4 cannot move axially, so that no injection action will be generated. That is, when the injection device is adjusted to increase or decrease the injection dose during non-injection, no injection activity will be generated under the limitation of the clutch 3 and the housing 1.

[0064] When injection is required, the clutch 3 is switched to the second axial position. At this time, the third limiting portion 31 of the clutch 3 is disengaged from the first limiting portion 11 of the housing 1, thereby releasing the limiting effect of the housing 1 on the clutch 3, so that the clutch 3 and the housing 1 can rotate radially relative to each other, that is, the clutch 3 can move circumferentially, thereby allowing the radial wheel 2 to move circumferentially. In this way, the radial wheel 2 can avoid interfering with the circumferential movement of the push rod 4, thereby allowing the push rod 4 to move axially smoothly. When the push rod 4 is rotated in the first direction, the push rod 4 synchronously moves toward the injection end of the housing 1 to achieve injection.

[0065] It can be seen that the injection device provided by the embodiment of the present invention switches the clutch 3 between the first axial position and the second axial position to make the clutch 3 engage or disengage with the housing 1. When the clutch 3 engages with the housing 1, the housing 1 is used to limit the clutch 3, thereby indirectly limiting the push rod 4, so that the push rod 4 will not produce an injection action when the injection is not in progress; when the clutch 3 is separated from the housing 1, the limiting effect of the housing 1 on the clutch 3 is released, so that the push rod 4 can be smoothly injected. At the same time, the fourth limiting portion 32 is always used to limit with the second limiting portion 21, so that the clutch 3 always maintains a synchronous circumferential position with the radial wheel 2, that is, the clutch 3 and the push rod 4 are indirectly always connected in circumferential motion, so that the state of the push rod 4 can be ensured by limiting or releasing the clutch 3 by the housing 1. The clutch transmission structure is simple, with few parts and components, and the transmission is simple and reliable.

[0066] It should be noted that the present embodiment does not limit the specific structures of the first position limiting portion 11, the second position limiting portion 21, the third position limiting portion 31 and the fourth position limiting portion 32, as long as the first position limiting portion 11 can cooperate with the third position limiting portion 31 for limiting, and the second position limiting portion 21 can cooperate with the fourth position limiting portion 32 for limiting.

[0067] Please refer to Figure 3 In some embodiments, the first limiting portion 11 is an inner edge annular tooth provided on the inner wall of the housing 1; the third limiting portion 31 is a first outer spline provided on the outer periphery of the clutch 3. That is to say, in this embodiment, the clutch 3 is combined with the housing 1 by the meshing of the inner edge annular tooth and the first outer spline, thereby realizing the limiting of the clutch 3 by the housing 1; when the clutch 3 is located in the first axial position, the first outer spline is meshed with the inner edge annular tooth to realize the circumferential limiting of the clutch 3 and the housing 1, so that the clutch 3 cannot rotate under the limiting of the housing 1; when the clutch 3 is located in the second axial position, the first outer spline is disengaged from the inner edge annular tooth, and the circumferential limiting between the clutch 3 and the housing 1 is released, so that the clutch 3 can rotate relative to the housing 1.

[0068] Please refer to Figure 2 In some embodiments, the second limiting portion 21 is a second outer spline provided on the outer periphery of the radial wheel 2, and the fourth limiting portion 32 is an inner spline provided on the inner periphery of the clutch 3, and the inner spline and the second outer spline are slidably matched. That is to say, the inner spline and the second outer spline are matched and can move axially relative to each other, and the matching length of the inner spline and the second outer spline is greater than the relative movement range between the two, so that the inner spline and the second outer spline are always in a matching state, so that the clutch 3 can move axially relative to the radial wheel 2, and the radial wheel 2 and the clutch 3 always have circumferential limit. In other words, the radial wheel 2 and the clutch 3 can slide relative to each other in the axial direction, but the two are never separated, so that the radial wheel 2 and the clutch 3 can always keep synchronous rotation or synchronous stop.

[0069] In addition, the above embodiment does not limit the specific implementation method of switching the clutch 3 between the first axial position and the second axial position, as long as the clutch 3 can be switched between the first axial position and the second axial position.

[0070] Please refer to Figure 4 In some embodiments, the injection device further comprises a driving rod 5 and a button 6, wherein the driving rod 5 is axially connected to the clutch 3; the button 6 is axially connected to the driving rod 5, and the button 6 is pressably arranged on the housing 1, so that when the button 6 is pressed, the driving rod 5 drives the clutch 3 to move from the first axial position to the second axial position. In other words, when the clutch 3 needs to be switched from the first axial position to the second axial position, the button 6 can be pressed. After pressing the button 6, the button 6 drives the driving rod 5 to move toward the injection end of the injection device, so that the driving rod 5 drives the clutch 3 to move toward the injection end, thereby switching the clutch 3 from the first axial position to the second axial position, and the operation is simple.

[0071] It should be noted that the present embodiment does not limit the specific connection method between the button 6 and the driving rod 5, as long as the axial connection between the two can be achieved. Fig.13 In some embodiments, a fourth protrusion 57 is provided on the inner side of the end of the driving rod 5 away from the injection end, and an end convex circle 61 is provided on the end of the button 6 close to the injection end. The end convex circle 61 is used to be inserted into the driving rod 5 so that the side of the end convex circle 61 away from the injection end abuts and limits the side of the fourth protrusion 57 close to the injection end. That is, in this embodiment, the end convex circle 61 of the button 6 abuts and limits the fourth protrusion 57 of the driving rod 5 to limit the axial position of the button 6 and prevent the button 6 from being separated from the driving rod 5.

[0072] Also, please refer to Figure 4 , Figure 6 , Figure 7 , Fig.10 and Fig.11In order to facilitate the driving of the push rod 4 to move so as to achieve injection, in some embodiments, the injection device further includes a sleeve 7 and a power elastic member 8. The sleeve 7 is arranged in the housing 1, and the sleeve 7 is provided with a spring pawl 71. The clutch 3 is provided with a first ratchet 33, and the spring pawl 71 extends into the first tooth groove of the first ratchet 33; the power elastic member 8 is connected between the sleeve 7 and the housing 1, and the power elastic member 8 has a preset torsional preload force so that the sleeve 7 always has a tendency to rotate in the first direction relative to the housing 1, so that after the clutch 3 is separated from the housing 1, the sleeve 7 drives the clutch 3 to rotate synchronously in the first direction. That is to say, in this embodiment, the clutch 3 limits the rotation of the sleeve 7 along the first direction through the cooperation between the spring piece pawl 71 and the first ratchet tooth 33, while the clutch 3 has no limiting effect on the rotation of the sleeve 7 along the second direction. That is, when the sleeve 7 rotates along the first direction, it drives the clutch 3 to rotate synchronously along the first direction, and when the sleeve 7 rotates along the second direction, the sleeve 7 can rotate in the second direction relative to the clutch 3, so that the clutch 3 does not rotate, and the second direction is opposite to the first direction. That is, in this embodiment, the clutch 3 is connected to the sleeve 7 through the cooperation between the spring piece pawl 71 and the first ratchet tooth 33, so that the sleeve 7 and the clutch 3 can realize the unidirectional synchronous rotation along the first direction and the unidirectional relative rotation along the second direction. When the third limiting portion 31 is disengaged from the first limiting portion 11, the clutch 3 is separated from the housing 1. At this time, under the preset torsional preload of the dynamic elastic member 8, the sleeve 7 is rotated in the first direction, and the spring pawl 71 pushes the first ratchet 33 to rotate synchronously, so that the clutch 3 and the sleeve 7 rotate synchronously in the first direction, and the clutch 3 is always combined with the radial wheel 2, and the radial wheel 2 and the push rod 4 are circumferentially limited. Therefore, when the clutch 3 rotates, it can drive the radial wheel 2 and the push rod 4 to rotate synchronously in the first direction. When the push rod 4 rotates in the first direction, it moves synchronously toward the injection end of the housing 1 to achieve injection.

[0073] That is to say, when injecting, you only need to press the button 6. After pressing the button 6, the clutch 3 moves from the first axial position to the second axial position, and the housing 1 releases the position limit of the clutch 3. At this time, under the preset torsional preload of the dynamic elastic member 8, the sleeve 7 drives the clutch 3, the radial wheel 2 and the push rod 4 to rotate synchronously in the first direction, thereby moving the push rod 4 toward the injection end to achieve injection.

[0074] It should be noted that this embodiment does not limit the specific connection methods of the dynamic elastic member 8 with the sleeve 7 and the housing 1. Figure 4 and Figure 6In some embodiments, the sleeve 7 is provided with a first slot 72, the housing 1 is provided with a shell cover 14, the shell cover 14 is provided with a second slot, and the two ends of the power elastic member 8 are respectively provided with a first bending portion and a second bending portion, the first bending portion is hooked with the first slot 72, and the second bending portion is hooked with the second slot, so as to realize the connection between the power elastic member 8 and the sleeve 7 and the housing 1 respectively, and the connection structure is simple and convenient. Considering the simplicity of the specific structure of the power elastic member 8, in some embodiments, the power elastic member 8 is a spring.

[0075] In addition, when the clutch 3 is in the first axial position and is combined with the housing 1, in order to facilitate the bidirectional rotation of the sleeve 7 to adjust the injection dose, please refer to Figure 8 , Fig.10 and Fig.11 In some embodiments, the injection device further comprises a pawl device 9, which is fixedly connected to the driving rod 5. The pawl device 9 is provided with a pawl side wall 91 located on the outside of the spring claw 71. The wall thickness of the pawl side wall 91 gradually increases from one side to the other side along the circumferential direction. When the clutch 3 is in the first axial position and the driving rod 5 rotates along the first direction, the pawl side wall 91 squeezes the spring claw 71, so that the spring claw 71 disengages from the first tooth groove, so that the pawl device 9 drives the sleeve 7 to rotate synchronously along the first direction.

[0076] It can be understood that when the clutch 3 is in the first axial position, the clutch 3 is combined with the housing 1, and the clutch 3 cannot rotate under the limit of the housing 1. In order to prevent the interference sleeve 7 from rotating in the first direction when the clutch 3 is in the first axial position, the present embodiment is provided with a pawl device 9. When the clutch 3 is in the first axial position, when the drive rod 5 rotates in the first direction, the pawl side wall 91 is used to squeeze the spring pawl 71, so that the spring pawl 71 is separated from the first tooth groove, thereby releasing the combination relationship between the sleeve 7 and the clutch 3, making the two independent of each other. At this time, when the drive rod 5 rotates in the first direction, the pawl device 9 drives the sleeve 7 to rotate synchronously in the first direction. It should be noted that, in some embodiments, the injection device includes a dose indicator, the sleeve 7 and the dose indicator can rotate synchronously, and the dose indicator can move axially relative to the sleeve 7. In addition, the dose indicator is threadedly connected to the housing 1 so that the dose indicator moves synchronously when rotating, thereby adjusting the injection dose of the injection device. When the sleeve 7 rotates in a first direction, it drives the dose indicator to rotate synchronously in the first direction, thereby achieving the purpose of reducing the injection dose; when the sleeve 7 rotates in a second direction opposite to the first direction, since the sleeve 7 and the clutch 3 are connected to the first ratchet 33 through the spring piece pawl 71, the spring piece pawl 71 and the first ratchet 33 limit the sleeve 7 and the clutch 3 to rotate synchronously in the first direction, while in the second direction, there is no limitation between the sleeve 7 and the clutch 3. At this time, the sleeve 7 can rotate freely in the second direction, thereby causing the sleeve 7 to drive the dose indicator to rotate synchronously in the second direction, thereby achieving the purpose of increasing the injection dose.

[0077] That is to say, when the clutch 3 is in the first axial position, by rotating the drive rod 5 and cooperating with the action of the pawl 9, combined with the matching structure of the spring pawl 71 and the first ratchet 33, the sleeve 7 can be rotated bidirectionally relative to the clutch 3, thereby realizing the reduction or increase of the injection dose.

[0078] It should be noted that the present embodiment does not limit the specific connection method between the driving rod 5, the sleeve 7, the clutch 3 and the pawl device 9, as long as the relative motion relationship required above can be ensured.

[0079] Please refer to Figure 5-Figure 11 In some embodiments, the end of the driving rod 5 close to the injection end is provided with at least two end clamps 51 distributed along the same circumference, the outer periphery of the end clamp 51 is provided with a first protrusion 52 and a second protrusion 53 arranged at intervals along the axial direction, and the outer periphery of the driving rod 5 is also provided with a third protrusion 54 arranged at intervals along the axial direction with the second protrusion 53; the clutch 3 is provided with a radially inwardly convex inner flange 34, the inner flange 34 and the spring pawl 71 are respectively arranged in the gap between the first protrusion 52 and the second protrusion 53, so that the clutch 3, the sleeve 7 and the driving rod 5 are axially limited and connected; the pawl device 9 is stuck in the gap between the second protrusion 53 and the third protrusion 54, and one of the pawl device 9 and the driving rod 5 is provided with a limiting notch 92, and the other is provided with a limiting rib 55 that cooperates with the limiting notch 92 for limiting.

[0080] That is to say, in this embodiment, the clutch 3, the sleeve 7 and the driving rod 5 are connected together by the end clamp 51 cooperating with the first protrusion 52 and the second protrusion 53, and the inner flange 34 and the spring pawl 71 are respectively arranged in the gap between the first protrusion 52 and the second protrusion 53, so that the axial positions of the clutch 3, the sleeve 7 and the driving rod 5 are relatively fixed, so that the clutch 3 and the sleeve 7 can move axially synchronously with the driving rod 5, and in addition, the clutch 3 and the sleeve 7 can rotate circumferentially relative to the driving rod 5, respectively, so as to avoid the driving rod 5 interfering with the rotational movement of the sleeve 7 and the clutch 3. In addition, the axial fixation of the pawl 9 and the driving rod 5 is realized by the second protrusion 53 and the third protrusion 54, and the circumferential fixation of the pawl 9 and the driving rod 5 is realized by the cooperation of the limiting rib 55 and the limiting notch 92, so that the pawl 9 and the driving rod 5 are completely fixed, so that the pawl 9 can move and rotate axially with the driving rod 5.

[0081] Considering the convenience of assembly, please refer to Fig.12In some embodiments, the pawl device 9 and the driving rod 5 are integrally processed and formed. That is to say, in this embodiment, the structure of the pawl device 9 is integrated on the driving rod 5, so that the pawl device 9 and the driving rod 5 are combined into an integrated structure. In this way, during assembly, the pawl device 9 and the driving rod 5 can be avoided from being assembled, which reduces the assembly steps, simplifies the assembly process, facilitates the assembly of the injection device, and improves the assembly efficiency.

[0082] Of course, if Figure 5 , Figure 8 , Figure 9-11 As shown, the specific connection structure when the clamping claw device 9 and the driving rod 5 are of a split structure is given.

[0083] In addition, in order to facilitate the rotation of the driving rod 5, please refer to Fig.14 In some embodiments, the housing 1 is provided with a rotatable knob 10, one of the drive rod 5 and the knob 10 is provided with a protruding tooth 56, and the other is provided with a tooth groove 101. When the button 6 is not pressed, the protruding tooth 56 cooperates with the tooth groove 101, and when the button 6 is pressed, the protruding tooth 56 disengages from the tooth groove 101. That is, when the button 6 is not pressed, the protruding tooth 56 cooperates with the tooth groove 101, so that the drive rod 5 is combined with the knob 10. At this time, by rotating the knob 10, the drive rod 5 can be rotated, which is convenient for operation. When the drive rod 5 rotates, the purpose of adjusting the injection dose can be achieved. When the button 6 is pressed, the protruding tooth 56 disengages from the tooth groove 101, so that the drive rod 5 is separated from the knob 10. At this time, the limit of the knob 10 on the drive rod 5 can be released, so that the drive rod 5 can rotate relative to the knob 10, so that the knob 10 will not rotate synchronously when the drive rod 5 rotates, avoiding the knob 10 from interfering with the movement of the drive rod 5.

[0084] It should be noted that the embodiment of the present invention does not limit the specific connection method between the knob 10 and the housing 1 and the button 6 and the housing 1, as long as it can ensure that the knob 10 is rotatably arranged on the housing 1 and the button 6 is pressably arranged on the housing 1.

[0085] In addition, after the injection is completed, in order to facilitate the reset of button 6, please refer to Fig.13In some embodiments, a reset spring 12 is provided between the button 6 and the housing 1, and the reset spring 12 is used to provide an elastic force to the button 6 to keep it away from the injection end. That is to say, when the button 6 is pressed, the button 6 generates an extrusion force on the reset spring 12, compressing the reset spring 12 and providing an elastic force. When the button 6 is released, the elastic force of the reset spring 12 acts on the button 6, causing the button 6 to move in a direction away from the injection end, thereby resetting the button 6 to facilitate the next press. It is understandable that when the button 6 is reset, the drive rod 5 is driven to reset synchronously, and then the drive rod 5 drives the clutch 3, the sleeve 7 and the pawl 9 to reset synchronously, so that the clutch 3 moves from the second axial position to the first axial position, thereby realizing the combination of the clutch 3 and the housing 1.

[0086] In order to facilitate the arrangement of the return spring 12 , in some embodiments, the return spring 12 is arranged between the button 6 and the knob 10 .

[0087] In addition, in order to facilitate the button 6 to drive the driving rod 5 to reset, in some embodiments, the sleeve 7 is axially connected to the driving rod 5, and the power elastic member 8 also has a preset axial tensile force, so that when the button 6 is released, the power elastic member 8 drives the sleeve 7 to drive the driving rod 5 to reset. That is to say, in this embodiment, when the power elastic member 8 is installed, not only the power elastic member 8 has a preset torsional preload force, but also the power elastic member 8 has a preset axial tensile force, so that when the injection is completed and the button 6 is released, under the action of the preset axial tensile force of the power elastic member 8, the sleeve 7 can drive the driving rod 5 to move away from the injection end, and then the driving rod 5 drives the clutch 3 and the button 6 to reset, so that the clutch 3 moves away from the injection end, so that the clutch 3 switches from the second axial position to the first axial position, and the clutch 3 is combined with the housing 1.

[0088] In addition, in the above-mentioned embodiments, the specific connection method between the push rod 4 and the housing 1 is not limited, as long as the push rod 4 can be rotated and axially moved at the same time.

[0089] Please refer to Figure 4 and Fig.18 In some embodiments, a cam 13 is provided in the housing 1, and the cam 13 is provided with an internal thread 131. The outer periphery of the push rod 4 is provided with two rows of intermittent helical teeth 41 distributed along the axial direction to form an intermittent external thread, and the external thread is threadedly connected with the internal thread 131. That is to say, in this embodiment, by providing the cam 13 in the housing 1 and connecting the push rod 4 with the cam 13, the push rod 4 is indirectly connected with the housing 1; at the same time, by providing the internal thread 131 on the cam 13, the threaded cooperation between the helical teeth 41 on the outer periphery of the push rod 4 and the internal thread 131 is utilized to realize the push rod 4 can spirally rotate relative to the cam 13, so that the push rod 4 can rotate while moving axially. The structure is simple and convenient for realizing the movement of the push rod 4.

[0090] Further, in order to facilitate the relative movement between the push rod 4 and the radial wheel 2, please refer to Figure 15-17 In some embodiments, a limiting guide groove 42 extending in the axial direction is provided between the two rows of spiral teeth 41, and the radial wheel 2 is provided with a radial inner protrusion 22 for slidingly cooperating with the limiting guide groove 42. That is to say, in this embodiment, the radial inner protrusion 22 cooperates with the limiting guide groove 42 to realize the circumferential limiting of the radial wheel 2 and the push rod 4, so that the radial wheel 2 can rotate synchronously with the push rod 4, and at the same time, the radial wheel 2 can move axially relative to the push rod 4, so that the push rod 4 can rotate and move axially at the same time, and the radial wheel 2 can be prevented from interfering with the axial movement of the push rod 4.

[0091] For further information, please refer to Fig.18 and Fig.19 In order to facilitate the radial wheel 2 to rotate relative to the housing 1 in the first direction, in some embodiments, the cam 13 is provided with a second ratchet 132, and the radial wheel 2 is provided with an elastic arm 23, and the elastic arm 23 extends into the second tooth groove of the second ratchet 132. It can be understood that the radial wheel 2 can be limited to unidirectional rotation relative to the cam 13 through the cooperation between the elastic arm 23 and the second ratchet 132. In this embodiment, the radial wheel 2 can be limited to rotate relative to the cam 13 in the first direction, and in the second direction, because the cam 13 is fixed to the housing 1, the radial wheel 2 cannot rotate in the second direction under the limiting effect of the second ratchet 132 on the elastic arm 23.

[0092] It should also be noted that, in this specification, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0093] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0094] The above is a detailed introduction to the injection device provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, the present invention can also be improved and modified without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. An injection device, characterized in that: include: The housing (1) is provided with a first limiting portion (11); A radial wheel (2) is arranged in the housing (1) so as to be rotatable along a first direction and is provided with a second limiting portion (21); The clutch (3) is provided with a third limiting portion (31) and a fourth limiting portion (32), and can be switched between a first axial position and a second axial position, the fourth limiting portion (32) always cooperates with the second limiting portion (21) for limiting, when the clutch (3) is located at the first axial position, the third limiting portion (31) cooperates with the first limiting portion (11) for limiting, so that the clutch (3) and the housing (1) are relatively fixed, when the clutch (3) is located at the second axial position, the third limiting portion (31) is disengaged from the first limiting portion (11), so that the clutch (3) and the housing (1) can rotate relative to each other in the radial direction; The push rod (4) is circumferentially limited with the radial wheel (2) and can move axially relative to the radial wheel (2); the push rod (4) moves axially synchronously with the circumferential rotation.

2. The injection device according to claim 1, characterized in that Also includes: A driving rod (5) axially connected to the clutch (3); A button (6) is axially connected to the drive rod (5) and is pressably arranged on the housing (1), so that when the button (6) is pressed, the drive rod (5) drives the clutch (3) to move from the first axial position to the second axial position.

3. The injection device according to claim 2, characterized in that Also includes: A sleeve (7) is arranged in the housing (1); the sleeve (7) is provided with a spring-type ratchet (71); the clutch (3) is provided with a first ratchet tooth (33); the spring-type ratchet (71) extends into a first tooth groove of the first ratchet tooth (33); A dynamic elastic member (8) is connected between the sleeve (7) and the housing (1) and has a preset torsional preload force, so that the sleeve (7) always has a tendency to rotate in a first direction relative to the housing (1), so that after the clutch (3) is separated from the housing (1), the sleeve (7) drives the clutch (3) to rotate synchronously in the first direction.

4. The injection device according to claim 3, characterized in that Also includes: A pawl device (9) is fixedly connected to the drive rod (5), the pawl device (9) is provided with a pawl side wall (91) located outside the spring-type pawl (71), the wall thickness of the pawl side wall (91) gradually increases from one side to the other side along the circumferential direction, and when the clutch (3) is in the first axial position and the drive rod (5) rotates along the first direction, the pawl side wall (91) squeezes the spring-type pawl (71) so that the spring-type pawl (71) is separated from the first tooth groove, so that the pawl device (9) drives the sleeve (7) to rotate synchronously along the first direction.

5. The injection device according to claim 4, characterized in that The end of the driving rod (5) close to the injection end is provided with at least two end clamps (51) distributed along the same circumference, the outer periphery of the end clamps (51) is provided with a first protrusion (52) and a second protrusion (53) arranged in an axial direction at intervals, and the outer periphery of the driving rod (5) is also provided with a third protrusion (54) arranged in an axial direction at intervals from the second protrusion (53); The clutch (3) is provided with a radially inwardly convex inner flange (34), and the inner flange (34) and the spring pawl (71) are respectively arranged in a gap between the first protrusion (52) and the second protrusion (53), so that the clutch (3), the sleeve (7) and the drive rod (5) are axially limitedly connected; The pawl device (9) is clamped in the gap between the second protrusion (53) and the third protrusion (54), and one of the pawl device (9) and the driving rod (5) is provided with a limiting notch (92), and the other is provided with a limiting rib (55) that cooperates with the limiting notch (92) to limit the position.

6. The injection device according to claim 4, characterized in that The claw device (9) and the driving rod (5) are an integrally processed structure or a split structure.

7. The injection device according to claim 2, characterized in that The housing (1) is provided with a rotatable knob (10); one of the driving rod (5) and the knob (10) is provided with a protruding tooth (56), and the other is provided with a tooth groove (101); when the key (6) is not pressed, the protruding tooth (56) is engaged with the tooth groove (101); when the key (6) is pressed, the protruding tooth (56) is disengaged from the tooth groove (101).

8. The injection device according to claim 3, characterized in that A return spring (12) is provided between the button (6) and the housing (1), and the return spring (12) is used to provide an elastic force to the button (6) to move it away from the injection end; and / or, The sleeve (7) is axially connected to the drive rod (5), and the dynamic elastic member (8) also has a preset axial tensile force, so that when the button (6) is released, the dynamic elastic member (8) drives the sleeve (7) to drive the drive rod (5) to reset.

9. The injection device according to any one of claims 1 to 8, characterized in that: The first limiting portion (11) is an inner edge annular tooth provided on the inner wall of the housing (1); the third limiting portion (31) is a first outer spline provided on the outer periphery of the clutch (3); And / or, the second limiting portion (21) is a second outer spline provided on the outer periphery of the radial wheel (2), the fourth limiting portion (32) is an inner spline provided on the inner periphery of the clutch (3), and the inner spline is slidably engaged with the second outer spline.

10. The injection device according to any one of claims 1 to 8, characterized in that: A cam (13) is provided in the housing (1), the cam (13) is provided with an internal thread (131), and the outer periphery of the push rod (4) is provided with two rows of intermittent helical teeth (41) distributed along the axial direction to form an intermittent external thread, and the external thread is threadedly connected to the internal thread (131); A limiting guide groove (42) extending in the axial direction is provided between the two rows of spiral teeth (41), and the radial wheel (2) is provided with a radial inner protrusion (22) for slidingly engaging with the limiting guide groove (42); and / or, The cam (13) is provided with a second ratchet tooth (132), and the radial wheel (2) is provided with an elastic arm (23), wherein the elastic arm (23) extends into a second tooth groove of the second ratchet tooth (132), so that the radial wheel (2) can rotate relative to the cam (13) along a first direction.

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