1. An electric parking brake device comprising:
an electric motor;
a conversion mechanism provided in a housing for converting a rotational drive force given by the electric motor into a linear drive force; and
at least one cable for transmitting the linear drive force from the conversion mechanism to at least one parking brake;
wherein the at least one parking brake is brought into a braking state when the at least one cable is drawn in a drawing direction by the operation of the electric motor in a positive-going direction, but is brought into a release state when the at least one cable is returned in a return direction by the operation of the electric motor in a reverse direction, the device further comprising:
a clutch mechanism for transmitting the rotation of the electric motor to the conversion mechanism, but for blocking the rotation transmission from the conversion mechanism toward the electric motor; and
auxiliary force applying means for conserving energy in the return direction of the at least one cable and for applying an auxiliary force depending on the energy, in the drawing direction of the at least one cable.
2. The electric parking brake device as set forth in claim 1, wherein the conversion mechanism includes a screw shaft rotatable by the electric motor, and wherein a large lead screw is formed on the external surface of the screw shaft.
3. The electric parking brake device as set forth in claim 1, wherein the maximum auxiliary force (Fsm) of the auxiliary force applying means is smaller than the maximum tension (Fbm) of the at least one cable.
4. The electric parking brake device as set forth in claim 1, wherein the auxiliary force applying means comprises an elastic member.
5. The electric parking brake device as set forth in claim 4, wherein:
the conversion mechanism includes a movable member connected to the at least one cable and movable in the moving direction of the at least one cable; and
the elastic member comprises either a compression spring or a tension spring which is arranged between the movable member and the housing.
6. The electric parking brake device as set forth in claim 5, wherein:
the at least one cable comprises a pair of cables for transmitting the linear drive force from the conversion mechanism to a pair of parking brakes including the at least one parking brake;
the conversion mechanism includes a screw shaft rotatable by the electric motor and having a large lead screw formed on the external surface thereof and a nut engaged on the large lead screw to be reciprocatively movable along the screw shaft; and
the movable member is an equalizer pivotally carried on the nut and connected to the pair of cables at opposite ends thereof.
7. The electric parking brake device as set forth in claim 2, wherein:
the auxiliary force applying means comprises a torsion spring arranged between the screw shaft and the housing for urging the screw shaft to rotate.
8. An electric parking brake device comprising:
a housing;
an electric motor mounted on the housing;
a conversion mechanism provided in the housing for converting a rotational drive force given by the electric motor into a linear drive force and including a linear motion member movable to reciprocate along a linear path upon operation of the electric motor;
an equalizer pivotably carried on the linear motion member and extending opposite end portions thereof in a direction transversal to the linear path;
a pair of cables respectively connected to the opposite end portions of the equalizer for transmitting the movement of the linear motion member to a pair of parking brakes;
wherein the parking brakes are brought into a braking state when the cables are drawn in a drawing direction by the operation of the electric motor in a positive-going direction, but is brought into a release state when the cables are returned in a return direction by the operation of the electric motor in a reverse direction, the device further comprising:
a clutch mechanism for transmitting the rotation of the electric motor to the conversion mechanism to reciprocate the linear motion member, but for blocking the rotation transmission from the conversion mechanism toward the electric motor; and
auxiliary force applying means for conserving energy in the return direction of the cables, but applying an auxiliary force depending on the energy, in the drawing direction of the cables.
9. The electric parking brake device as set forth in claim 8, wherein the conversion mechanism further includes:
a screw shaft rotatable by the electric motor and having a large lead screw formed on the external surface thereof; and
a nut engaged on the large lead screw to operate as the linear motion member;
wherein the auxiliary force applying means is arranged to urge the linear motion member in the drawing direction of the cables.
10. The electric parking brake device as set forth in claim 9, wherein the auxiliary force applying means comprises either a compression spring or a tension spring which is arranged between the equalizer and the housing.
11. The electric parking brake device as set forth in claim 9, wherein the auxiliary force applying means comprises a torsion spring arranged between the screw shaft and the housing for urging the screw shaft to rotate in the drawing direction of the cables.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An ink jet printing apparatus that forms an image by using a print head having a plurality of ejection ports, comprising:
a wiping member that removes ink adhered around the ejection ports;
dissolving means that dissolves ink adhered to the wiping member by ejecting predetermined ink to the wiping member;
counting means that counts a number of ejections of ink ejected from the ink ejection ports; and
control means that controls the dissolving means so that a number of ejections of the predetermined ink ejected by the dissolving means in a case where the number counted by the counting means is greater than or equal to a threshold is increased to be greater than a number of ejections of the predetermined ink ejected by the dissolving means in a case where the number counted by the counting means is less than the threshold.
2. An ink jet printing apparatus according to claim 1, wherein the predetermined ink is ink in which viscosity does not increase easily.
3. An ink jet printing apparatus according to claim 1, wherein the predetermined ink is light cyan ink.
4. An ink jet printing apparatus according to claim 1, wherein the dissolving means ejects a single or a plurality of kinds of ink from the print head to the wiping member.
5. An ink jet printing apparatus according to claim 1, wherein the dissolving means ejects the ink from the print head to the wiping member in synchronism with a sliding motion of the wiping member on an ejection port face of the print head.
6. An ink jet printing apparatus that forms an image by using a print head having a plurality of ejection ports, comprising:
a wiping member that removes ink adhered around the ejection ports;
dissolving means that dissolves ink adhered to the wiping member by applying a predetermined liquid to the wiping member;
counting means that counts a number of ejections of ink ejected from the ink ejection ports; and
control means that changes an amount of the predetermined liquid to be applied by the dissolving means according to the ejection number counted by the counting means.
7. An ejection performance recovery device for recovering an ejection performance of a print head in an ink jet printing apparatus, wherein the ink jet printing apparatus forms an image by using a print head having a plurality of ejection ports, the ejection performance recovery device comprising:
a wiping member that removes ink adhered around the ejection ports;
dissolving means that dissolves ink adhered to the wiping member by ejecting predetermined ink to the wiping member;
counting means that counts a number of ejections of ink ejected from the ink ejection ports; and
control means that controls the dissolving means so that a number of ejections of the predetermined ink ejected by the dissolving means in a case where the number counted by the counting means is greater than or equal to a threshold is increased to be greater than a number of ejections of the predetermined ink ejected by the dissolving means in a case where the number counted by the counting means is less than the threshold.
8. An ejection performance recovery method for recovering an ejection performance of a print head in an ink jet printing apparatus, wherein the ink jet printing apparatus forms an image by using a print head having a plurality of ejection ports, the ejection performance recovery method comprising:
a wiping step of removing ink adhered around the ejection ports by using a wiping member;
a dissolving step of dissolving ink adhered to the wiping member by ejecting predetermined ink to the wiping member;
a counting step of counting a number of ejections of ink ejected from the ink ejection ports; and
a control step of controlling the dissolving step so that a number of ejections of the predetermined ink ejected in the dissolving step in a case where the number counted in the counting step is greater than or equal to a threshold is increased to be greater than a number of ejections of the predetermined ink ejected in the dissolving step in the case where the number counted in the counting step is less than the threshold.
9. An ejection performance recovery device for recovering an ejection performance of a print head in an ink jet printing apparatus, wherein the ink jet printing apparatus forms an image by using a print head having a plurality of ejection ports, the ejection performance recovery device comprising:
a wiping member that removes ink adhered around the ejection ports;
dissolving means that dissolves the ink adhered to the wiping member by applying a predetermined liquid to the wiping member;
counting means that counts a number of ejections of ink from the ink ejection ports; and
control means that changes an amount of the predetermined liquid to be applied by the dissolving means according to the ejection number counted by the counting means.
10. An ejection performance recovery method for recovering an ejection performance of a print head in an ink jet printing apparatus, wherein the ink jet printing apparatus forms an image by using a print head having a plurality of ejection ports, the ejection performance recovery method comprising:
a wiping step of removing ink adhered around the ejection ports by using a wiping member;
a dissolving step of dissolving ink adhered to the wiping member by applying a predetermined liquid to the wiping member;
a counting step of counting a number of ejections of ink ejected from the ink ejection ports; and
a control step of changing an amount of the predetermined liquid to be applied in the dissolving step according to the ejection number counted in the counting step.