Door latch device

Abstract

A door latch device 1 comprises a main unit 40 having an electric release mechanism 13 and a manual release-and-locking mechanism 9. An inner open lever 34 that is rotated by operating an inner handle 8 comprises an output unit 43c that can output a rotational force to an element other than an operation part 32a of a link 32. A joint 33 of the manual release-and-locking mechanism 9 comprises a groove hole 33b that receives an input for switching from a locked state to an unlocked state.

Description

Door latch device

[0001] The present invention relates to a door latch device.

[0002] The vehicle door latch device described in Patent Document 1 includes a locking mechanism that can switch between an active state (unlocked state) and an inactive state (locked state) when the handle is operated to open the door. The door latch device also includes an override mechanism and a child lock mechanism. The override mechanism is classified into a one-motion type and a two-motion type. A one-motion type override mechanism transitions from a locked state to an unlocked state with a single operation of the inner handle, and releases the latch mechanism. A two-motion type override mechanism transitions from a locked state to an unlocked state with a first operation of the inner handle, and releases the latch mechanism with a second operation of the inner handle. When the child lock mechanism is active, i.e., in the child lock state, the override mechanism does not function even when the inner handle is operated, and the locking mechanism remains locked, the latch mechanism is not released, and the door cannot be opened.

[0003] The vehicle door latch device described in Patent Document 2 includes an electric release mechanism that can electrically release the latch mechanism, a manual release mechanism that can manually release the latch, and a locking mechanism that can switch the manual release mechanism between enabled and disabled.

[0004] JP 2009-052229 A JP 2014-015765 A

[0005] The above functions are selected and combined according to requirements. Therefore, door latch devices must be individually designed and manufactured to combine these mechanisms, which increases manufacturing costs. There is a need to reduce costs by standardizing the basic structure between door latch devices that combine different mechanisms.

[0006] An object of the present invention is to standardize the basic structure of door latch devices.

[0007] One aspect of the present invention provides a door latch device comprising a main unit having an electric release mechanism that can electrically release a latch mechanism when an operation receiving unit located inside the vehicle receives an operation, an inner open lever that rotates in conjunction with the operation of an inner handle, an input unit that receives the rotational force of the inner open lever, an operation unit for releasing the latch mechanism by the rotational force received by the input unit, and a manual release and lock mechanism that includes a lock switching member that can switch between an unlocked state in which the operation unit can release the latch mechanism and a locked state in which the operation unit cannot release the latch mechanism, wherein the transmission of rotational force between the inner open lever and the input unit cannot be cut off, the inner open lever has an output unit that can output the rotational force to an element other than the input unit, and the manual release and lock mechanism has a receiving unit that receives an input for switching from the locked state to the unlocked state.

[0008] When used with only the main unit, the door latch device has both an electric release mechanism and a manual release mechanism. By associating the output portion of the inner open lever and the receiving portion of the manual release / lock mechanism with a mechanism provided in the sub-unit, functions other than the electric release mechanism and the manual release mechanism can be added. In other words, the main unit with the electric release mechanism and the manual release mechanism forms the basic structure, and this basic structure can be shared when functions are added with a sub-unit. This sharing of the basic structure can reduce costs, such as manufacturing costs.

[0009] According to the door latch device of the present invention, the basic structure can be standardized, thereby reducing costs such as manufacturing costs.

[0010] 1 is a block diagram showing the configuration of a door latch device according to an embodiment of the present invention (consisting of only a main unit); a schematic diagram of a manual release and lock mechanism (locked state); a schematic diagram of a manual release and lock mechanism (locked state); a schematic diagram of a manual release and lock mechanism (unlocked state); a schematic diagram of a manual release and lock mechanism (unlocked state). 1 is a block diagram showing the configuration of a door latch device according to an embodiment of the present invention (consisting of a main unit and a first sub-unit); a schematic diagram of a manual release and lock mechanism and an override mechanism (before the first inner handle pulling operation); a schematic diagram of a manual release and lock mechanism and an override mechanism (first inner handle pulling operation); a schematic diagram of a manual release and lock mechanism and an override mechanism (after the first inner handle pulling operation); a schematic diagram of a manual release and lock mechanism and an override mechanism (second inner handle pulling operation). 2 is a block diagram showing the configuration of a door latch device according to an embodiment of the present invention (consisting of a main unit and a second sub-unit); a schematic diagram of a manual release and lock mechanism, an override mechanism, and a child lock mechanism (before the first inner handle pulling operation in the child unlock state). Schematic diagram of the manual release and lock mechanism, override mechanism, and child lock mechanism (first inner handle pulling operation in child unlock state). Schematic diagram of the manual release and lock mechanism, override mechanism, and child lock mechanism (after first inner handle pulling operation in child unlock state). Schematic diagram of the manual release and lock mechanism, override mechanism, and child lock mechanism (second inner handle pulling operation in child unlock state). Schematic diagram of the manual release and lock mechanism, override mechanism, and child lock mechanism (before inner handle pulling operation in child lock state). Schematic diagram of the manual release and lock mechanism, override mechanism, and child lock mechanism (inner handle pulling operation in child lock state).

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0012] The door latch device 1 according to this embodiment is provided for locking and unlocking the doors of an automobile, which is an example of a vehicle, and can be used with only the main unit 40, as shown in Figures 1 and 2A. The door latch device 1 can also be used in combination with the main unit 40 and a first subunit 41, as shown in Figures 3 and 4A. Furthermore, the door latch device can also be used in combination with the main unit 40 and a second subunit 42, as shown in Figures 5 and 6A.

[0013] When the door latch device 1 is configured with only the main unit 40 (Configuration Example 1), it has an electric release mechanism, a manual release mechanism, an electric lock mechanism, and an emergency unlock mechanism. The electric release mechanism allows the engagement of the claw 5 with the fork 4 to be released by the driving force of the electric release motor 7. The manual release mechanism allows the engagement of the claw 5 with the fork 4 to be released by manual operation. The electric lock mechanism allows the locked state and the unlocked state to be switched by the driving force of the lock mechanism motor 10. The emergency unlock mechanism allows the locked state to be switched from the unlocked state by the driving force of the lock mechanism motor 10 when the remaining charge of the vehicle battery is low, for example.

[0014] When the main unit 40 and the first subunit 41 are used in combination (Configuration Example 2), the door latch device 1 has an override mechanism in addition to the electric release mechanism, manual release mechanism, electric locking mechanism, and emergency unlocking mechanism. The override mechanism makes it possible to switch from a locked state to an unlocked state and release the engagement of the claw 5 with the fork 4 by operating the inner handle 8. The override mechanism in this embodiment is a two-motion override that realizes switching from a locked state to an unlocked state and release of the engagement of the claw 5 with the fork 4 by operating the inner handle 8 twice.

[0015] When the main unit 40 and the second sub-unit 42 are used in combination (Configuration Example 3), the door latch device 1 has a child lock mechanism in addition to the electric release mechanism, manual release mechanism, electric lock mechanism, emergency unlock mechanism, and override mechanism. The child lock mechanism disables the override mechanism, making it impossible to switch from the locked state to the unlocked state by operating the inner handle 8.

[0016] Configuration examples 1 to 3 will be described below in order.

[0017] A description will be given of Configuration Example 1. As described above, in Configuration Example 1, the door latch device 1 is composed of only the main unit 40.

[0018] 1 and 2A, a door is provided with a latch mechanism 2. The latch mechanism 2 includes a fork 4 that releasably holds a striker 3 provided on the vehicle body. The fork 4 is rotatable about an axis 4a and is elastically biased clockwise in the drawings. The latch mechanism 2 also includes a claw 5 that can be engaged with and disengaged from the fork 4 and can engage with the fork 4 to maintain an engaged state between the fork 4 and the striker 3. The claw 5 is rotatable about an axis 5a and is elastically biased counterclockwise in FIG. 1. The engagement of the claw 5 with the fork 4 can be released by moving the operating portion 5b of the claw 5 clockwise (upward in FIG. 2A).

[0019] The main unit 40 includes a main case 40a. The main case 40a houses an electric release mechanism 13 and a manual release and lock mechanism 9. The main case 40a also houses a lock mechanism motor 10, and the manual release and lock mechanism 9 and the lock mechanism motor 10 constitute an electric lock mechanism.

[0020] The electric release mechanism 13 includes an electric release lever 6 and an electric release motor 7. The rotational drive force of the electric release motor 7 is transmitted to the electric release lever 6, which rotates to operate the operating portion 5b of the claw 5, thereby disengaging the claw 5 from the fork 4. Specifically, the electric release lever 6 is rotatably supported on a shaft 6a provided in the main case 41a. The electric release lever 6 is provided with a gear portion 6b. A worm gear 7a attached to the output shaft of the electric release motor 7 is engaged with the gear portion 6b. The rotational output of the electric release motor 7 is transmitted to the electric release lever 6 via the worm gear 7a and gear portion 6b, which rotates the electric release lever 6 and operates the operating portion 5b of the claw 5 to move upward in FIG. 2A . An unlatch switch (operation receiving unit) 15 receives an unlatch instruction operation from the occupant and outputs an unlatch signal. Upon receiving the unlatch signal, the control unit 20 drives the electric release motor 7 to rotate the electric release lever 6, thereby disengaging the claw 5 from the fork 4.

[0021] As described above, the manual release mechanism is made up of the inner handle 8 and the manual release and locking mechanism 9. Specifically, when the manual release and locking mechanism 9 is in an unlocked state, the operating portion 5b of the claw 5 can be moved upward in Figure 2A via the manual release and locking mechanism 9 by operating the inner handle 8, thereby releasing the engagement of the claw 5 with the fork 4.

[0022] As described above, the electric locking mechanism is composed of the manual release and locking mechanism 9 and the locking mechanism motor 10. Specifically, the manual release and locking mechanism 9 can be switched between an unlocked state and a locked state by being driven by the locking mechanism motor 10. The locking state changeover switch 16 accepts a locking instruction operation or an unlocking instruction operation by the occupant and outputs a locking signal or an unlocking signal. Upon receiving the locking signal or the unlocking signal, the control unit 20 rotates the locking mechanism motor 10 so as to rotate in the direction corresponding to the signal received. This switches the manual release and locking mechanism 9 between a locked state and an unlocked state, as will be described later.

[0023] The emergency unlock mechanism is composed of an emergency sensor 19, a control unit 20, a locking mechanism motor 10, and a manual release and locking mechanism 9. The emergency sensor 19 detects an emergency that requires the claw 5 to be disengaged from the fork 4 by operating the inner handle 8, and outputs an emergency signal. The emergency signal is received by the control unit 20. Examples of emergency situations that can be detected by the emergency sensor 19 include a collision of the vehicle with another vehicle or an obstacle, the vehicle being submerged in water, and a low on-board battery. When the control unit 20 receives the emergency signal, it drives the locking mechanism motor 10 to operate the manual release and locking mechanism 9, switching the manual release and locking mechanism 9 from a locked state to an unlocked state.

[0024] In the case of configuration example 1, the door latch device 1 includes, as switches and sensors, an unlatch switch 15, a lock state changeover switch 16, a lock state detection switch (lock member position detection unit) 18, and an emergency sensor 19. Signals output by these switches are input to a control unit 20, which controls the electric release motor 7 and the lock mechanism motor 10 based on the input signals.

[0025] 2A and 2C, the manual release and locking mechanism 9 will now be described.

[0026] The manual release and lock mechanism 9 includes a lock plate 31, a link 32, a joint 33, and an inner open lever 34.

[0027] The inner open lever 34 is rotatable around a shaft 34a provided on the main case 40a. The inner open lever 34 rotates clockwise in the figure in conjunction with the pulling operation of the inner handle 8. The inner open lever 34 is elastically biased counterclockwise by a spring (not shown). One arm 34d of the inner open lever 34 is rotatably connected to one end (the lower end in the figure) of the link 32 via a rotary joint 34e. The rotation of the inner open lever 34 is transmitted to the link 32 via the rotary joint 34e. In other words, the rotary joint 34e functions as an input part through which the link 32 receives the rotational force of the inner open lever 34. The transmission of rotational force from the inner open lever 34 to the link 32 via the rotary joint 34e cannot be cut off. The other arm 34b of the inner open lever 34 is provided with an output part 34c that can output rotational force to an element other than the link 32.

[0028] The lock plate 31 is rotatable around a shaft 31a provided on the main case 40a. The lock plate 31 includes an arm 31b that overlaps the other end (the upper end in the figure) of the link 32, and an arm 31c that overlaps one end (the upper end in the figure) of the joint 33. The arm 31b is connected to the other end of the link via a spring 35. Specifically, one end of the spring 35 is engaged with the lock plate 31, and the other end of the spring 35 extends beyond the tip of the arm 31b and is inserted into a slot 32b provided in the other end of the link 32, and is held movably along the slot 32b.

[0029] The link 32 is provided with an operating portion 32a for operating the operating portion 5b of the claw 5. When the link 32 moves upward in the drawing, the operating portion 32a pushes up the operating portion 5b, thereby releasing the engagement of the claw 5 with the fork 4.

[0030] The joint 33 is held in the main case 40a so that it can only move linearly (up and down in the figure). One end (the upper end in the figure) of the joint 33 has a slot 33a extending laterally. A cylindrical pin 31d on an arm 31c of the lock plate 31 is inserted into this slot 33a, connecting one end of the joint 33 to the lock plate 31. When the joint 33 rises, the lock plate 31 rotates counterclockwise, and when the joint 33 descends, the lock plate 31 rotates clockwise. The other end (the lower end in the figure) of the joint 33 also has a slot (input portion) 33b extending laterally. This slot 33b has the function of receiving an input for switching from a locked state to an unlocked state, as will be described later in connection with configuration examples 2 and 3.

[0031] The locking mechanism motor 10 can raise and lower the joint 33. Specifically, a gear 10a attached to the output shaft of the locking mechanism motor 10 engages with a gear portion (not shown) provided on the joint 33. The rotational output of the locking mechanism motor 10 is transmitted to the joint 33 via the gear 10a and the gear portion, and the joint 33 rises and falls depending on the rotation direction of the locking mechanism motor 10.

[0032] 2A shows the manual release and lock mechanism 9 in a locked state, i.e., when the lock plate 31 is in the locked position, and FIG. 2C shows the manual release and lock mechanism 9 in an unlocked state, i.e., when the lock plate 31 is in the unlocked position. In the locked state, the operating portion 32a of the link 32 and the operating portion 5b of the claw 5 are laterally offset from each other in the figure, but in the unlocked state, the operating portion 32a of the link 32 and the operating portion 5b of the claw 5 are laterally aligned in the figure.

[0033] 2A and 2C , the lock state detection switch 18 is in an OFF state when the manual release and lock mechanism 9 is in a locked state ( FIG. 2A ), but is pressed by the joint 33 to an ON state when the manual release and lock mechanism 9 is in an unlocked state ( FIG. 2C ), and outputs a lock switching signal indicating that the manual release and lock mechanism 9 has switched from the locked state to the unlocked state (movement of the lock plate 31 from the locked position to the unlocked position), and the output lock switching signal is received by the control unit 20. In this way, the lock state detection switch 18 of this embodiment indirectly detects that the lock plate 31 has moved from the locked position to the unlocked position based on the position of the joint 33. However, the lock state detection switch 18 may also directly detect the movement of the lock plate 31 from the locked position to the unlocked position based on the position of the lock plate 31, or may indirectly detect that the lock plate 31 has moved from the locked position to the unlocked position based on the position or posture of the link 32.

[0034] The operation of the door latch device 1 when the inner handle 8 is operated will be described below for the first configuration example.

[0035] 2A, when the inner handle 8 is pulled while the manual release and locking mechanism 9 is in the locked state, the inner open lever 34 rotates clockwise, which in turn moves the link 32 diagonally upward. As a result, the manual release and locking mechanism 9 is in the state shown in Fig. 2B. In the locked state, the operating portion 32a of the link 32 and the operating portion 5b of the claw 5 are misaligned in the lateral direction in the figure. Therefore, even if the link 32 rises, the operating portion 32a does not push up the operating portion 5b of the claw 5, and the manual release and locking mechanism 9 is maintained in the locked state, and the latch mechanism is maintained in the latched state.

[0036] 2C , when the inner handle 8 is pulled while the manual release and locking mechanism 9 is in the unlocked state, the inner open lever 34 rotates clockwise, which in turn moves the link 32 upward. As a result, the manual release and locking mechanism 9 enters the state shown in FIG. 2D . In the unlocked state, the operating portion 32 a of the link 32 and the operating portion 5 b of the claw 5 are aligned horizontally in the figure, so when the link 32 rises, the operating portion 32 a pushes up the operating portion 5 b of the claw 5, and the engagement of the claw 5 with the fork 4 is released. In other words, the mechanism enters the unlatched state.

[0037] Note that the user can normally operate the unlatch switch 15 to unlatch the latch mechanism 2 using the electric release mechanism 13, eliminating the need to operate the inner handle 8. Therefore, the manual release and locking mechanism 9 is normally fixed in the locked state. However, in an emergency such as a collision of the vehicle with another vehicle or an obstacle, submersion of the vehicle in water, or a low on-board battery, the control unit 20 and the electric release mechanism 13 may become inoperable. In such an event, the emergency unlock mechanism switches the manual release and locking mechanism 9 from the locked state to the unlocked state before the control unit 20 and the electric release mechanism 13 become inoperable, allowing the latch mechanism 2 to be unlatched by operating the inner handle 8.

[0038] Next, a description will be given of Configuration Example 2. As described above, in Configuration Example 2, the door latch device 1 is composed of the main unit 40 and the first sub-unit 41.

[0039] 3 and 4A, the first subunit 41 includes a first sub-case 41a. The first sub-case 41a is detachably fixed to the lower end of the main mace 40a in FIG. 4A. The override mechanism 11 is housed in the first sub-case 41a.

[0040] The override mechanism 11 includes an override lever 36. The override lever 36 is rotatable around a shaft 36a provided on the first sub-case 41a. One arm (engagement portion) 36b of the override lever 36 is operated by the output portion 34c of the inner open lever 34 described above. When the inner open lever 34 rotates clockwise in the figure, the output portion 34c presses the arm 36b, causing the override lever 36 to rotate counterclockwise. The other arm 36c of the override lever 36 is provided with a cylindrical pin (operation portion) 36d. The pin 36d is inserted into a groove 33b at the other end (the lower end in the figure) of the joint 33, connecting the arm 36c of the override lever 36 to the other end of the joint 33. When the override lever 36 rotates counterclockwise, the joint 33 rises.

[0041] The operation of the door latch device 1 when the inner handle 8 is operated will be described below for the second configuration example.

[0042] Referring to FIG. 4A , when the manual release and lock mechanism 9 is in the locked state and the inner handle 8 is pulled for the first time, the inner open lever 34 rotates clockwise, and the link 32 moves diagonally upward in response. As the inner open lever 34 rotates clockwise, the output portion 34c of the inner open lever 34 pushes the arm 36b of the override lever 36, rotating it counterclockwise. This rotation of the override lever 36 also raises the joint 33. As a result, as shown in FIG. 4B , the lock plate 31 rotates counterclockwise at the joint 33, and the lock plate 31 moves from the locked position to the unlocked position. In addition, in the state shown in FIG. 4B , the operating portion 32a of the link 32 interferes with the operating portion 5b of the claw 5, preventing the link 32 from moving toward the operating portion 5b together with the lock plate 31, and the spring 35 remains compressed.

[0043] When the first pulling operation of the inner handle 8 is stopped in the state shown in Figure 4B, the inner open lever 34 rotates counterclockwise due to the elastic biasing force, causing the link 32 to descend. Furthermore, as the link 32 descends, interference between the operating part 32a and the operating part 5a of the claw 5 is eliminated, and the link 32 rotates clockwise around the rotational joint 34e due to the biasing force of the spring 35. As a result, as shown in Figure 4C, the lock plate 31 is in the unlocked position, and the operating part 32a is aligned with the operating part 5b of the claw 5 laterally in the figure, i.e., the unlocked state is reached.

[0044] When the inner handle 8 is pulled a second time in the unlocked state shown in Fig. 4C, the inner open lever 34 rotates clockwise, and in conjunction with this, the link 32 moves upward. As a result, as shown in Fig. 4D, the operating part 5b of the claw 5 is pushed up by the operating part 32a of the link 32, and the claw 5 is released from the lock on the fork 4. In other words, the unlatched state is achieved.

[0045] Next, a description will be given of Configuration Example 3. As described above, in Configuration Example 3, the door latch device 1 is composed of the main unit 40 and the second sub-unit 42.

[0046] 5 and 6A, the second subunit 42 includes a second sub-case 42a. The second sub-case 42a is detachably fixed to the lower end of the main case 40a in FIG. 6A. The override mechanism 11 and the child lock mechanism 22 are housed in the second sub-case 42a.

[0047] The override mechanism 11 in configuration example 3 differs from that in configuration example 2 only in that the override lever 36 does not include the arm 36b (see, for example, FIG. 4A ) but includes an arm 36c with a pin 36d. The pin 36d is inserted into the slot 33b of the joint 33.

[0048] The child lock mechanism 22 is disposed between the inner open lever 34 and the override lever 36. The child lock mechanism 22 includes a sub-open lever 51. The sub-open lever 51 is disposed coaxially with the override lever 36. In other words, the sub-open lever 51 is rotatable together with the override lever 36 around a shaft 36a provided in the second sub-case.

[0049] One arm 51a of the sub-opening lever 51 is operated by the output part 34c of the inner open lever 34, and when the output part 34c presses the arm 51a due to clockwise rotation of the inner open lever 34 in the drawing, the sub-opening lever 51 rotates counterclockwise. The other arm 51b of the sub-opening lever 51 faces the arm 36c of the override lever 36.

[0050] The child lock mechanism 22 includes a spring 52 that elastically biases the sub-open lever 51 clockwise around the shaft 36a.

[0051] The child lock mechanism 22 includes a child lock switch knob (switching member) 53. The child lock switch knob 53 is rotatably supported on the second sub-case 42a and configured to be rotatable from outside the vehicle. The child lock switch knob 53 includes an arm 53a and a boss 53b provided at the tip of the arm 53a. The child lock switch knob 53 is provided with a protrusion 53c that protrudes radially.

[0052] The child lock mechanism 22 includes a spring 54 that regulates the orientation or rotation angle position of the child lock switch knob 53. When no external force is applied to the child lock switch knob 53, it can be set to either a position where the protrusion 53c is clockwise from the end of the spring 54 (child unlock position) as shown in FIG. 6A, or a position where the protrusion 53c is counterclockwise from the end of the spring 54 (child lock position) as shown in FIG. 7A. When the child lock switch knob 53 is in the child unlock position, the child lock mechanism 22 is in the child unlock state. When the child lock switch knob 53 is in the child lock position, the child lock mechanism 22 is in the child lock state.

[0053] As shown in Fig. 6A, when the child lock switching knob 53 is in the child unlock position (child unlock state), the boss 53b is located between the arm 51b of the sub-opening lever 51 and the arm 36c of the override lever 36. On the other hand, as shown in Fig. 7A, when the child lock switching knob 53 is in the child lock position (child lock state), the boss 53b is located outside the area where the arm 51b of the sub-opening lever 51a and the arm 36c of the override lever 36 face each other.

[0054] The door latch device 1 of configuration example 3 includes a child lock detection switch 17. The child lock detection switch 17 is in an OFF state when the child lock switching knob 53 is in the child unlock position (FIG. 6A), but is pressed down by the arm 53a to an ON state when the child lock switching knob 53 is in the child lock position (FIG. 7A), and outputs a signal indicating that the child lock mechanism 22 has been switched from the child unlock state to the child lock state. This output signal is received by the control unit 20.

[0055] 6A , when the child lock mechanism 22 is in the child unlock state and the manual release and lock mechanism 9 is in the locked state, pulling the inner handle 8 for the first time rotates the inner open lever 34 clockwise, and in response, the link 32 moves diagonally upward. Furthermore, the clockwise rotation of the inner open lever 34 causes the operating portion 34c of the inner open lever 34 to push the arm 51a of the sub-open lever 51, rotating it counterclockwise. The counterclockwise rotation of the sub-open lever 51 is transmitted to the arm 36c of the override lever 36 via the child lock switch knob 53. Specifically, the arm 51a of the sub-open lever 51 is pushed by the operating portion 34c, causing the sub-open lever 51 to rotate counterclockwise, and the arm 51b pushes the boss 53b, causing the child lock switch knob 53 to rotate clockwise. Furthermore, the clockwise rotation of the child lock switch knob 53 causes the boss 53b to push the arm 36b of the override lever 36c, rotating the override lever 36 counterclockwise. Furthermore, this rotation of the override lever 36 raises the joint 33. As a result, as shown in Fig. 6B, the lock plate 31 is rotated counterclockwise by the joint 33, and the lock plate 31 moves from the locked position to the unlocked position. In addition, in the state shown in Fig. 6B, the operating portion 32a of the link 32 interferes with the operating portion 5a of the claw 5, so the link 32 cannot move toward the operating portion 5b together with the lock plate 31, and the spring 35 is held in a compressed state.

[0056] When the first pulling operation of the inner handle 8 is stopped in the state shown in Figure 6B, the inner open lever 34 rotates counterclockwise due to the elastic biasing force, causing the link 32 to descend. Furthermore, as the link 32 descends, interference between the operating part 32a and the operating part 5b of the claw 5 is eliminated, and the link 32 rotates clockwise around the rotational joint 34e due to the biasing force of the spring 35. As a result, as shown in Figure 6C, the lock plate 31 is in the unlocked position, and the operating part 32a is aligned with the operating part 5b of the claw 5 laterally in the figure, i.e., the unlocked state is reached.

[0057] When the inner handle 8 is pulled a second time in the unlocked state shown in Fig. 6C, the inner open lever 34 rotates clockwise, and in conjunction with this, the link 32 moves upward. As a result, as shown in Fig. 6D, the operating part 5b of the claw 5 is pushed up by the operating part 32a of the link 32, and the claw 5 is released from the lock on the fork 4. In other words, the unlatched state is achieved.

[0058] 7A , when the child lock mechanism 22 is in the child lock state and the manual release and lock mechanism 9 is in the locked state, pulling the inner handle 8 rotates the inner open lever 34 clockwise, and the operating portion 34c of the inner open lever 34 pushes the arm 51a of the sub-opening lever 51, rotating it counterclockwise. However, because the boss 53b of the child lock switch knob 53 is located outside the area where the arm 51b of the sub-opening lever 51a and the arm 36c of the override lever 36 face each other, the rotation of the sub-opening lever 51 is not transmitted to the override lever 36, and the joint 33 does not rise. As a result, as shown in FIG. 7B , the lock plate 31 remains in the locked position. In other words, the manual release and lock mechanism 9 remains locked. The inner open lever 34 rotates clockwise, and in conjunction with this, the link 32 moves diagonally upward, but since the operating part 32a of the link 32 and the operating part 5b of the claw 5 are misaligned in the horizontal direction in the figure, even when the link 32 rises, the operating part 32a does not push up the operating part 5b of the claw 5.

[0059] Note that a user can normally operate an unlatch switch 15 located inside the vehicle to use the electric release mechanism 13 to set the latch mechanism 2 to an unlatched state, eliminating the need to operate the inner handle 8. Therefore, the manual release and locking mechanism 9 is normally fixed in a locked state. However, in an emergency such as a collision of the vehicle with another vehicle or an obstacle, submersion of the vehicle in water, or a low on-board battery, the control unit 20 and the electric release mechanism 13 may become inoperable. In such an event, the emergency unlocking mechanism switches the manual release and locking mechanism 9 from the locked state to the unlocked state before the control unit 20 and the electric release mechanism 13 become inoperable, allowing the latch mechanism 2 to be unlatched by operating the inner handle 8.

[0060] Furthermore, as described above, because the manual release and locking mechanism 9 is normally fixed in the locked state, there is no need for the child lock mechanism 22 to switch between coupling and disengagement between the inner open lever 34 and the rotary joint (input unit) 34e. That is, for example, if the manual release and locking mechanism 9 is not fixed in the locked state and is normally in the unlocked state, the latch mechanism 2 will be unlatched by operating the inner open lever 34 even if the child lock mechanism 22 is in the child lock state. However, in configuration example 3, because the manual release and locking mechanism 9 is normally fixed in the locked state, there is no need for the child lock mechanism 22 to switch between coupling and disengagement between the inner open lever 34 and the rotary joint (input unit) 34e. Instead, it is sufficient for the child lock mechanism 22 to simply switch between coupling and disengagement between the inner open lever 34 and the override lever 36. Therefore, by simply combining the second subunit 41 with the main unit 40, an override mechanism and a child lock mechanism can be added to the main unit 40.

[0061] As described above, when the door latch device 1 of this embodiment is configured with only the main unit 40 (Configuration Example 1), it has an electric release mechanism and a release mechanism. Furthermore, when the main unit 40 and the first subunit 41 are combined (Configuration Example 2), the door latch device 1 further has an override mechanism formed by the engagement between the output portion 34c of the inner opening lever 34 and the arm 36b of the override lever 36, and the engagement of the pin 36d of the override lever 36 with the slot 33b of the joint 33. Furthermore, when the main unit 40 and the second subunit 41 are combined (Configuration Example 3), the door latch device 1 further has an override mechanism and a child lock mechanism formed by the engagement between the output portion 34c of the inner opening lever 34 and the arm 51a of the sub-opening lever 51, and the cooperation of the arm 51b of the sub-opening lever 51, the arm 36c of the override lever 36, and the boss 53b of the child lock switch knob 53. In other words, the door latch device 1 of this embodiment has a basic structure that is a main unit having an electric release mechanism and a manual release function, and this basic structure can be shared with cases where functions are added to the first sub-unit 41 and the second sub-unit 42. By sharing this basic structure, it is possible to reduce costs such as manufacturing costs.

[0062] In the above embodiment, the first subunit case 41a and the second subunit case 42a are detachably fixed to the main case 40a, but the main case 40a may be provided in advance with the mechanisms provided in the first subunit 41 and the second subunit 42, i.e., structures such as shafts for providing the override mechanism 11 and the child lock mechanism 22. In other words, the first subunit case 40a and the second subunit case 40b may be integrated with the main case 40a.

[0063] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0064] DESCRIPTION OF SYMBOLS 1 Door latch device 2 Latch mechanism 3 Striker 4 Fork 4a Shaft 5 Claw 5a Shaft 5b Operating unit 6 Electric release lever 6a Shaft 6b Gear unit 7 Electric release motor 7a Worm gear 8 Inner handle 9 Manual release and locking mechanism 10 Locking mechanism motor 10a Gear 11 Override mechanism 13 Electric release mechanism 15 Unlatch switch (operation receiving unit) 16 Lock state changeover switch 17 Child lock detection switch 18 Lock state detection switch (lock member position detection unit) 19 Emergency sensor 20 Control unit 22 Child lock mechanism 31 Lock plate (lock switching member) 31a Shaft 31b Arm 31c Arm 31d Pin 32 Link 32a Operating unit 23b Long groove 33 Joint 33a Slot 33b Groove (receiving portion) 34 Inner open lever 34a Shaft 34b Arm 34c Output portion 34d Arm 34e Rotational joint (input portion) 35 Spring 36 Override lever 36a Shaft 36b Arm 36c Arm 36d Pin 40 Main unit 40a Main case 41 First subunit 41a First subunit case 42 First subunit 42a Second subunit case 51 Sub-open lever 51a Arm 51b Arm 52 Spring 53 Child lock switch knob 53a Arm 53b Boss 53c Protrusion 54 Spring

Claims

1. A door latch device comprising: a main unit having an electric release mechanism that can electrically release the latch mechanism when an operation receiving unit located inside the vehicle receives an operation; an inner open lever that rotates in conjunction with the operation of the inner handle; an input unit that receives the rotational force of said inner open lever; an operation unit for releasing the latch mechanism by the rotational force received by said input unit; and a manual release and lock mechanism including a lock switching member that can switch between an unlocked state in which the operation unit can release the latch mechanism and a locked state in which the operation unit cannot release the latch mechanism, wherein the transmission of rotational force between said inner open lever and said input unit cannot be cut off; said inner open lever has an output unit that can output the rotational force to an element other than said input unit; and said manual release and lock mechanism has a receiving unit that receives an input for switching from the locked state to the unlocked state.

2. The door latch device according to claim 1, further comprising a first subunit provided with an override mechanism having an override lever that receives rotational force from the output portion of the inner open lever to operate the lock switching member and switch the manual release and lock mechanism from the locked state to the unlocked state.

3. A door latch device as described in claim 2, wherein the override lever is rotatably supported, and the override lever comprises: an engagement portion that rotates the override lever by receiving the rotational force of the inner open lever from the output portion of the inner open lever; and an operation portion that operates the lock switching member via the receiving portion by the rotation of the override lever, and can switch the manual release and lock mechanism from the locked state to the unlocked state.

4. The door latch device according to claim 1, further comprising a second subunit having: an override mechanism having an override lever that receives a rotational force from the output portion of the inner open lever to operate the lock switching member and switch the manual release and lock mechanism from the locked state to the unlocked state; and a child lock mechanism that is disposed between the inner open lever and the override lever and is switchable between a child unlock state in which the rotational force of the inner open lever can be transmitted to the override lever and a child lock state in which the rotational force of the inner open lever cannot be transmitted to the override lever without affecting the transmission of the rotational force from the inner open lever to the input portion.

5. A door latch device as described in claim 4, wherein the child lock mechanism comprises: a sub-open lever that is rotatably supported and receives a rotational force from the output portion of the inner open lever; and a switching member that enables the sub-open lever to transmit the rotational force of the inner open lever to the override lever in the child unlock state, and disables the sub-open lever from transmitting the rotational force of the inner open lever to the override lever in the child lock state.

6. The door latch device according to claim 5, wherein the sub-open lever is disposed coaxially with the override lever.

7. A door latch device as described in claim 3, wherein the main unit comprises a main case that houses the electric release mechanism, the inner open lever, and the manual release and lock mechanism, and the first sub-unit comprises a first sub-unit case that has a shaft that supports the override lever and houses the override mechanism, and is removably fixed to the main case.

8. A door latch device as described in claim 6, wherein the main unit comprises a main case that houses the electric release mechanism, the inner open lever, and the manual release and lock mechanism, and the second sub-unit comprises a second sub-unit case that has an axle that supports the sub-open lever and the override lever, houses the override mechanism and the child lock mechanism, and is removably fixed to the main case.

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