1. A pyrotechnic actuator, comprising:
a housing,
a piston slidable inside the housing,
an igniter disposed within the housing and causing the piston to slide,
the piston including a piston head having a pressure-receiving surface with which a combustion product, produced by actuation of the igniter, collides,
a piston rod extending from the piston head and further,
a resin portion provided at least in a part of the piston,
the resin portion being disposed in contact with a member including the housing,
the piston being fixed by contacting the resin portion to the member including the housing, and
the piston being prevented from moving before activation of the igniter.
2. The pyrotechnic actuator according to claim 1, wherein
the resin portion is a resin protrusion formed radially on the outer side of the piston, and
the resin protrusion is fixed by a combination of an inner wall surface of the housing and at least one of a cup member and a tubular member disposed inside the housing to fix the piston, whereby the piston is prevented from moving before the igniter is actuated.
3. The pyrotechnic actuator according to claim 1, wherein
the resin portion is a resin protrusion formed radially on the outer side of the piston,
a step portion is provided in an inner wall surface of the housing,
the piston is fixed in a state where the resin protrusion abuts against the step portion, and the piston is prevented from moving before the igniter is actuated.
4. The pyrotechnic actuator according to claim 1, wherein
the resin portion is a tubular member having an annular protrusion projecting from the inner circumferential surface of the resin member,
the piston head has an annular groove formed on the outer circumferential surface thereof,
an inner circumferential surface of the tubular member abuts against the outer circumferential surface of the piston head, and the annular protrusion of the tubular member is fitted into the annular groove of the piston head, whereby the piston and the tubular member are integrated, and
a circumferential edge of an open portion at one end side of the tubular member abuts against an annular step portion formed at the inner wall surface of the housing, whereby the piston is fixed and the piston is prevented from moving before the igniter is actuated.
5. The pyrotechnic actuator according to claim 1, wherein
the piston head has a non-through hole which is formed in a thickness direction in an apex surface of the piston head and which has at least the bottom portion thereof formed from a resin,
a cup member having a rod member provided to protrude from a bottom surface thereof is fixed on the circumference thereof by the inner wall surface of the housing and accommodated in combination with the piston head inside the housing, and
the rod member of the cup member is inserted into the non-through hole of the piston head, and a distal end portion of the rod member abuts against the bottom portion of the non-through hole, whereby the piston is fixed and the piston is prevented from moving before the igniter is actuated.
6. The pyrotechnic actuator according to claim 1 or 2, wherein a space formed inside the housing where the piston slides is set such that an inner diameter of one end portion where the piston head is located before actuating the igniter is smaller than an inner diameter of the opposite end portion, so that the piston head can be fitted into the smaller-diameter end portion.
7. The pyrotechnic actuator according to claim 1 or 2, wherein a pressure-receiving surface of the piston head has an area of 50% or more the area of the end surface including a central portion of an end surface of the piston head that faces the igniter.
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. A steering damper system of the liquid pressure in which a damping force is exerted on a front wheel steering system provided at a front portion of a vehicle body and which comprises:
a control valve for making said damping force variable;
said damping force is varied according to a variable quantity related to the magnitude of a kick-back forecasted in said front wheel steering system, and a reference value of said damping force varying linearly in proportion to said variable quantity is corrected according to the steering speed of said front wheel steering system.
2. The steering damper system as set forth in claim 1, wherein said variable quantity is said steering speed, a correction is conducted so that the correction amount becomes negative in relation to said reference value when said steering speed is low, and a correction is conducted so that the correction amount becomes positive in relation to said reference value when said steering speed is high.
3. The steering damper system as set forth in claim 1, wherein said damping force becomes constant when said steering speed has exceeded a predetermined threshold value.
4. The steering damper system as set forth in claim 1, wherein said control valve is a solenoid valve, and an upper limit restriction of said damping force is effected by an electromagnetic force of said solenoid valve.
5. The steering damper system as set forth in claim 1, wherein said steering damper includes a chamber with a vane disposed therein, said vane being moved in a first direction in relationship with a front wheel being moved in a first direction and said vane being moved in a second direction in relationship with a front wheel being moved in a second direction.
6. The steering damper system as set forth in claim 5, wherein said vane divides said chamber into a first section and a second section, a gap is provided between said vane and an inner wall of said chamber for providing communication of a fluid disposed within said chamber from either one of said first section to said second section and said second section to said first section.
7. The steering damper system as set forth in claim 6, wherein said steering damper system includes two control valves, a first control valve being operatively connected to said first section of said chamber and a second control valve being operatively connected to said second section of said chamber.
8. The steering damper system as set forth in claim 7, and further including a first flow rate sensor for sensing the flow of fluid from said first section of said chamber to said first control valve and a second flow rate sensor for sensing the flow of fluid from said second section of said chamber to said second control valve.
9. The steering damper system as set forth in claim 5, wherein said chamber is fan shaped.
10. The steering damper system as set forth in claim 1, and further including biasing means for normally biasing said valve body to an open position.
11. A steering damper system of the liquid pressure in which a damping force is exerted on a front wheel steering system provided at a front portion of a vehicle body and which comprises:
a control valve for providing a variable damping force for controlling kick-back on the front wheel steering system;
a variable quantity damping force being varied in accordance to a related magnitude of the kick-back forecasted in said front wheel steering system, and a reference value of said damping force varying linearly in proportion to said variable quantity is corrected according to the steering speed of said front wheel steering system.
12. The steering damper system as set forth in claim 11, wherein said control valve is a solenoid valve, and said upper limit restriction of said damping force is effected by an electromagnetic force of said solenoid valve.
13. The steering damper system as set forth in claim 11, wherein said steering damper includes a chamber with a vane disposed therein, said vane being moved in a first direction in relationship with a front wheel being moved in a first direction and said vane being moved in a second direction in relationship with a front wheel being moved in a second direction.
14. The steering damper system as set forth in claim 13, wherein said vane divides said chamber into a first section and a second section, a gap is provided between said vane and an inner wall of said chamber for providing communication of a fluid disposed within said chamber from either one of said first section to said second section and said second section to said first section.
15. The steering damper system as set forth in claim 14, wherein said steering damper system includes two control valves, a first control valve being operatively connected to said first section of said chamber and a second control valve being operatively connected to said second section of said chamber.
16. The steering damper system as set forth in claim 15, and further including a first flow rate sensor for sensing the flow of fluid from said first section of said chamber to said first control valve and a second flow rate sensor for sensing the flow of fluid from said second section of said chamber to said second control valve.
17. The steering damper system as set forth in claim 13, wherein said chamber is fan shaped.
18. The steering damper system as set forth in claim 11, and further including biasing means for normally biasing said valve body to an open position.
19. The steering damper system as set forth in claim 11, wherein said variable quantity is said steering speed, a correction is conducted so that the correction amount becomes negative in relation to said reference value when said steering speed is low, and a correction is conducted so that the correction amount becomes positive in relation to said reference value when said steering speed is high.
20. The steering damper system as set forth in claim 11, wherein said damping force becomes constant when said steering speed has exceeded a predetermined threshold value.