JP4046040B2 - Shock absorber with power supply function between sprung and unsprung - Google Patents

Description

  The present invention relates to a shock absorber having a power feeding function between sprung and unsprung parts.

In recent years, a large number of electric vehicle vehicles are on the market from the viewpoint of environmental conservation, and in particular, small-sized vehicles such as home delivery vehicles and short mileage are spreading. Some of these vehicles have motors attached to the wheels with an emphasis on space utility. In addition, from the viewpoint of reducing brake fluid waste, electric brakes that are driven by an electric motor instead of hydraulic pressure have been studied.
In the electric vehicle and the electric brake described above, it is necessary to supply power to the electrical components mounted in the so-called unsprung portion, particularly the motor, in the vicinity of the tire of the vehicle from the vehicle body above the spring.
In the above-mentioned small electric vehicle, these electrical components are directly connected to the vehicle body side by electric wires. However, in ordinary passenger cars and the like, the suspension stroke is long from the viewpoint of ride comfort, and the motor capacity is large, so the electric wires are thick. .
Therefore, as a result of repeated deflection of the electric wire, there is a possibility that the electric wire may be broken due to fatigue.
As a solution to this problem, for example, a first coil is provided on the spring and a second coil is provided below the spring, and electric power is sent between the two in a non-contact manner by electromagnetic induction. A technique for supplying electric power between the two is known (see Patent Document 1).
Japanese Patent Laid-Open No. 11-18212

However, in the technique disclosed in Patent Document 1, the magnetic flux penetrating path of the first coil and the second coil, which is the most important as a transformer, is formed only by a non-magnetic material, and the power transmission efficiency is improved. It has a bad structure.
In addition, since it is newly added and attached to the outside of the shock absorber or in the middle of the suspension link, there is a possibility of interference with the components constituting the suspension, and there is a problem that it is difficult to attach.
Further, since electromagnetic induction is used, only AC power can be supplied. Therefore, for example, when driving a DC motor on the unsprung side, it is necessary to rectify by providing a bridge circuit on the unsprung side. In that case, there is a problem that it is impossible to cope with an operation in which the motor of the wheel is used as a generator when the vehicle is decelerated and the regenerative power is collected in the battery on the spring.
In order to solve the above-described problems, an object of the present invention is to provide a shock absorber having a power supply function between a sprung spring and an unsprung spring that can supply a direct current.

Therefore, the present invention provides a rod member that is fixed at one end to a sprung member of a vehicle, and a cylinder that is slidably accommodated at the other end of the rod member and is fixed to an unsprung member of the vehicle. In a shock absorber that generates a damping force by relative displacement with a member , the cylindrical member has an end cap on one end side of the rod member having a through hole through which the rod member passes through the center and can be slid liquid-tightly. A first electrode plate extending in an axial direction from one end side on the outer peripheral surface of the rod member, and a first brush disposed in a cavity facing the through hole of the end cap, Is in contact with and slides on the electrode plate to electrically connect the rod member side and the cylindrical member side.

According to the present invention, since the brush and the electrode plate opposed to the brush are used, both alternating current and direct current can be fed bidirectionally between the sprung springs.
Therefore, when a DC motor is used on the unsprung side, a simple configuration that does not require a rectifier circuit on the unsprung side can be achieved.

  Next, embodiments of the present invention will be described based on examples.

Hereinafter, a first embodiment of the present invention will be described with reference to FIG.
FIG. 1 shows a longitudinal section of a twin tube type shock absorber to which the present invention is applied.
The inner cylinder 10 and the outer cylinder 11 that are arranged in the inner and outer layers are connected to each other at the upper end and the lower end by an end cap 12 and a base valve 13, and the lower end of the outer cylinder 11 is liquid-tightly closed by an end cover 14. The gas is sealed in the upper part of the reservoir chamber 18 in the annular space between the inner cylinder 10 and the outer cylinder 11. The reservoir chamber 18 and the space P below the base valve 13 are connected by a communication hole 16.
As will be described later, the gas sealed in the upper portion of the reservoir chamber 18 is for absorbing a change in the volume of the piston rod 20 described later in the inner cylinder 10 when the shock absorber is expanded and contracted.

In the inner cylinder 10, a piston 17 that separates the working chamber in the inner cylinder 10 into a lower chamber R <b> 1 and an upper chamber R <b> 2 is slidably provided. It penetrates and projects above the inner cylinder 10 and the outer cylinder 11.
Although not shown, the upper end portion of the piston rod 20 is attached to a vehicle spring upper member, that is, a vehicle body side member, and the outer cylinder 11 or the end cover 14 is attached to a vehicle unsprung member, that is, a wheel side member. It is done.

The inner cylinder 10 is made of a conductive metal, and is connected to the end cap 12 and a harness 4b extending from the lead-out hole 31 provided in the outer cylinder 11 on the upper end side to the harness 4b. Connect to one terminal of electrical equipment.
Although not shown, the inner cylinder 10 and the end cap 12 are electrically insulated with resin or the like.

The piston rod 20 is provided with a hook-like rebound stopper 23 that restricts the maximum stroke (displacement) on the extension side of the piston 17 in the inner cylinder 10 at a position above the piston 17 by a predetermined distance.
Further, the piston rod 20 includes a brush holder 2 at a lower position of the rebound stopper 23 and a center hole 21 that reaches the brush holder 2 from the upper end of the piston rod 20.

The brush holder 2 fixed to the piston rod 20 has a brush chamber 2a that opens to the side facing the inner cylinder 10 around the piston rod 20, and has a spring 3 in the inside thereof and thereby attached radially outward. The brush 1 that is urged and slides on the inner peripheral surface of the inner cylinder 10 is accommodated. A hole 32 is provided in the piston rod 20 to connect the brush chamber 2 a and the center hole 21.
The brush holder 2 is equally spaced around the piston rod 20 so that the pressing force by the spring 3 between the brush 1 and the inner cylinder 10 does not bias the piston rod 20 in a direction deviating from the central axis of the inner cylinder 10. The brush chambers 2a are arranged radially.
FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1. In the brush holder 2, two brush chambers 2 a are arranged back to back at an interval of 180 °.

The brush 1 is electrically insulated from the spring 3 and the brush holder 2 by performing, for example, a resin coating process except for the surface that contacts the inner cylinder 10. The brush 1 is connected to one end of the harness 4a. The harness 4a reaches the upper end of the piston rod 20 via the hole 32 and the center hole 21, and further extends to the upper side of the spring, for example, is connected to one terminal of the power source.
The center hole 21 is passed through the harness 4a and filled with resin or the like, and is sealed so that the operating oil of the shock absorber does not leak.

  Above the rebound stopper 23 of the piston rod 20, the electrode plate member 8 made of a cylindrical conductor is insulated on the outer peripheral surface of the piston rod 20 with an insulating material (not shown) made of resin interposed. , Fixedly provided. The upper part of the electrode plate member 8 is connected to the harness 7a outside the end cap 12, and the harness 7a is further connected to, for example, the other terminal of the power source on the upper side of the spring.

The end cap 12 is provided with an oil seal 15 that allows the piston rod 20 to slide in a liquid-tight manner on the inner wall of the through hole 24, and a sliding seal 25 b that guides the piston rod below the oil seal 15. A dust seal 26 is provided above 15 to prevent dust.
Further, the end cap 12 has a communication hole 27 that connects the reservoir chamber 18 and the lower portion of the oil seal 15 in the through hole 24, and the hydraulic oil in the upper chamber R2 is discharged from the sliding seal 25b when the shock absorber is extended. The leakage is released to the reservoir chamber 18.
3 is a cross-sectional view taken along the line B-B of FIG. 1, and an upper end portion of the inner cylinder 10 opposite to the communication hole 27 is connected to the harness 4 b, and is extended upward.

Further, between the oil seal 15 and the dust seal 26, a brush holder portion 6, which is a cavity that opens to the through hole 24, is provided around the through hole 24, and the spring 3 is provided therein, thereby radially inwardly. The brush 5 that is urged and slides with the electrode plate member 8 on the outer peripheral surface of the piston rod 20 is housed. The brush 5 is electrically insulated from the spring 3 and the end cap 12 by performing, for example, a resin coating process except for the surface in contact with the electrode plate member 8.
The brush holder portion 6 has a lead-out hole 33 that communicates with the outside of the outer cylinder 11.
The brush holder portion 6 is arranged around the through hole 24 so that the pressing force by the spring 3 between the brush 5 and the electrode plate member 8 does not bias the piston rod 20 in a direction deviating from the central axis of the through hole 24. Arranged radially at intervals.
FIG. 4 is a cross-sectional view taken along the line CC of FIG. 1, and two brush holder portions 6 are arranged to face each other at an interval of 180 °.

The brush 5 is connected to one end of the harness 7b, and the harness 7b is drawn out from the brush holder portion 6 through the lead-out hole 33 and connected to the other terminal of the unsprung electrical component.
The brushes 1 and 5 are obtained by implanting a large number of thin conductive metal wires in a conductive member. The conductive metal of the brushes 1 and 5 is placed on the opposing electrode member, here the inner cylinder 10 or the electrode plate member 8. The thin wire elastically contacts and slides and is electrically connected. The harnesses 4a, 4b, 7a and 7b are conductors whose outer periphery is covered with an insulating material.

The base valve 13 is a leaf (not shown) that mainly generates a damping force by applying resistance to the flow from the lower chamber R1 of the hydraulic oil to the reservoir chamber 18 via the space P during operation on the contraction side, like a normal twin tube type shock absorber. A valve and a leaf valve (not shown) that introduces hydraulic oil in the reservoir chamber 18 into the lower chamber R1 via the space P during the extension side operation are provided.
Similarly, the piston 17 gives a resistance to the flow from the upper chamber R2 of the hydraulic oil to the lower chamber R1 during the expansion side operation and generates a damping force, and the operation in the lower chamber R1 during the contraction side operation. And a leaf valve (not shown) for introducing oil into the upper chamber R2. Further, the side surface of the piston 17 has a sliding seal 25 a that slides on the inner peripheral surface of the inner cylinder 10.
The main body of the base valve 13 and the sliding seal 25a are, for example, resin insulating members, and the inner cylinder 10 and the base valve 13 and the inner cylinder 10 and the piston 17 are electrically insulated.
In FIG. 1, the detailed structures of the base valve 13 and the piston 17 are omitted, and only the main body portions are shown.

The operation of this embodiment will be described below.
With the above configuration, the piston rod 20, the piston 17 attached thereto, the brush holder 2 and the rebound stopper 23, the electrode plate member 8, and the harnesses 4a and 7a are on the spring upper side. The rest is on the unsprung side.
Therefore, when the vehicle travels and relative displacement occurs between the sprung springs, the brush 1 slides with respect to the inner peripheral surface of the inner cylinder 10, and the brush 5 slides with the electrode plate member 8. . Between the brush 1 and the inner cylinder 10, and between the brush 5 and the electrode plate member 8, it is possible to slide not only in the axial direction of the shock absorber but also in the twist in the circumferential direction.
Since the conductive thin wire of the brush 1 is in contact with the inner cylinder 10 with elasticity, good electrical connection can be ensured even when immersed in the hydraulic oil. Further, since the conductive thin wire of the brush 5 is also in contact with the surface of the electrode plate member 8 from which the working oil has been removed by the oil seal 15, a good electrical connection can be ensured.

Therefore, when the power supplied between the sprung spring is DC, for example, a direct current is supplied from the harness 4a, transmitted to the inner cylinder 10 via the brush 1, and further supplied from the harness 4b to the unsprung electrical components. The
The return current from the electrical component is transmitted from the harness 7b to the electrode plate member 8 via the brush 5, further transmitted to the spring-side harness 7a, and returns to the negative electrode of the power source.
In this embodiment, the piston rod 20 constitutes a rod member of the present invention, the inner cylinder 10 and the end cap 12 constitute a cylindrical member, and the inner cylinder 10 and the electrode plate member 8 constitute an electrode plate.
In particular, the electrode plate member 8 corresponds to the first electrode plate of the present invention, the brush 5 corresponds to the first brush, the inner cylinder 10 corresponds to the second electrode plate, and the brush 1 corresponds to the second brush.

As described above, according to the present embodiment, power is supplied between the sprung spring and the unsprung portion between the brush 1 and the inner cylinder 10 facing the brush 1 and the electrode plate member 8 facing the brush 5. Therefore, the transmission efficiency is better than that by electromagnetic induction.
In addition, because the harness does not bend due to the expansion and contraction of the shock absorber, even if there is expansion or contraction between the sprung springs, the harness will not be bent and fatigue will not occur. Can be prevented from being damaged.

When this shock absorber is used as a strut for a strut suspension that is used in large numbers for the front suspension of a steered wheel of a vehicle, the outer cylinder 11 is attached not to a suspension link but to an axle member that rotates together with the steered wheel. In this case, the piston rod of the shock absorber and the inner cylinder and the outer cylinder are not only expanded and contracted in the axial direction, but also relatively rotated around the axis of the shock absorber.
Since the structure between the brush 1 and the inner cylinder 10 of the shock absorber and between the brush 5 and the electrode plate member 8 is slidable not only in the axial direction but also in the circumferential direction, simultaneously with expansion and contraction of the shock absorber. The rotation in the circumferential direction accompanying the turning can be absorbed, and it is particularly preferable to apply to the strut.
In the present embodiment, the main body of the piston 17, the end cap 12, and the brush holder 2 may be made of resin and electrically insulated from the inner cylinder 10 or the brushes 1 and 5.

Next, a second embodiment will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
In the first embodiment, the inner cylinder 10 is made of a conductor and itself constitutes one electrode plate. However, in this embodiment, the inner cylinder 10 'interposes an insulating material (not shown), and Three electrode plate members 8 ′ that are insulated and extend in the axial direction are arranged on the inner peripheral surface in the circumferential direction and fixed to form independent electrodes.
The electrode plate member 8 ′ has a circumferential width corresponding to, for example, 115 ° in angle and is arranged at equal intervals of 120 °.
Note that the electrode plate member 8 ′ and the end cap 12 ′ are electrically insulated with resin or the like although not shown. The main body of the base valve 13 and the sliding seal 25a are, for example, resin insulating members, and are electrically insulated between the electrode plate member 8 ′ and the base valve 13, and between the electrode plate member 8 ′ and the piston 17. The

The piston rod 20 ′ is provided with a brush holder 2 ′ at the lower position of the rebound stopper 23 as in the first embodiment. As shown in FIG. 6 which is a cross-sectional view taken along the line DD in FIG. 5, the brush holder 2 ′ has three brush chambers 2a ′ facing each electrode plate member 8 ′ and around the piston rod 20 ′. Are provided radially at intervals of 120 ° in the circumferential direction.
The brush 1 is housed in each brush chamber 2a ′, and is urged outward of the brush holder 2 ′ by a spring 3 built in the brush holder 2 ′, and slides on the electrode plate member 8 ′.

The brush 1 is electrically insulated from the spring 3 and the brush holder 2 ′ by, for example, a resin coating process except for the surface that contacts the electrode plate member 8 ′. The brush 1 is connected to the end of the harness 4a, and the three harnesses 4a reach the upper end of the piston rod 20 ′ via the hole 32 and the central hole 21 of the piston rod 20 ′.
In addition, the width | variety of the part contact | abutted with electrode plate member 8 'of the brush 1 shall be 20 degrees by the angle of the circumferential direction, for example. The center hole 21 is filled with resin so that hydraulic oil does not leak.

In the first embodiment, the electrode plate member 8 is provided on the outer peripheral surface of the piston rod 20 above the rebound stopper 23, and the end cap 12 is provided with the brush holder 6 that accommodates the brush 5 and the spring 3. In the present embodiment, these are not provided.
In the present embodiment, the oil seal 15 of the end cap 12 ′ serves both as dustproof and liquid-tight.
In this embodiment, the piston rod 20 'constitutes a rod member of the present invention, and the inner cylinder 10' and the end cap 12 'constitute a cylindrical member.

Also according to the present embodiment, current can be transmitted while sliding between the brush 1 attached on the upper side of the spring and the electrode plate member 8 'on the lower side of the spring.
Further, the electrode plate member 8 ′ is divided into three parts in the circumferential direction and insulated from each other and provided with three harnesses 4a and 4b, respectively. An inverter for controlling and supplying the AC power can be arranged.

In the present embodiment, the width of the brush 1 in the circumferential direction is set to 20 ° in angle, and the electrode plate member 8 ′ is set to have a circumferential width equivalent to 115 ° in angle. It can be rotated up to ± 47.5 °.
Since the normal turning angle is ± 45 °, the shock absorber of this embodiment can be applied to the struts of the front suspension in the case of a structure in which up to three electrode plate members 8 ′ are provided.
In the present embodiment, the main body of the piston 17, the end cap 12 ′, and the brush holder 2 ′ may be made of resin and electrically insulated from the electrode plate member 8 ′ or the brush 1.

As a modification based on the second embodiment, the configurations of the brush 5 of the end cap 12 of the first embodiment and the electrode plate member 8 facing the piston rod 20 are modified and combined as follows. May be.
For example, the electrode plate member 8 is divided into two parts by being insulated from each other in the circumferential direction, and the harness 7a is connected to each of the divided electrode plate members 8 and the harness 7b connected to the opposing brush 5 is connected to the plus side and minus side of the direct current. Alternatively, it is configured as a first system of single-phase alternating current, and the second of three-phase alternating current by the three brushes 1 of the inner cylinder 10 ′ of the second embodiment and the three electrode plate members 8 ′ facing each brush 1. With the system, a power supply line between the sprung sprung having two systems in total can be configured.

  In addition, although the 1st Example and the 2nd Example showed by the example applied to the twin tube type shock absorber, it is not limited to it, It can apply also to a single tube type shock absorber.

It is a longitudinal cross-sectional view which shows the whole structure of the 1st Example in this invention. It is an AA section sectional view of Drawing 1. It is a BB section sectional view of FIG. It is CC sectional view taken on the line of FIG. It is a longitudinal cross-sectional view which shows the whole structure of a 2nd Example. FIG. 6 is a cross-sectional view taken along the line DD in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 5 Brush 2, 2 'Brush holder 2a, 2a' Brush chamber 3 Spring 4a, 4b, 7a, 7b Harness 6 Brush holder part 8, 8 'Electrode plate member 10, 10' Inner cylinder 11 Outer cylinder 12, 12 ' End cap 13 Base valve 14 End cover 15 Oil seal 16 Communication hole 17 Piston 18 Reservoir chamber 20, 20 'Piston rod 21 Center hole 23 Rebound stopper 24 Through hole 25a, 25b Sliding seal 26 Dust seal 27 Communication hole 31, 33 Drawer hole 32 holes

Claims (6)

A rod member whose one end is fixed to the sprung member of the vehicle and a cylindrical member that slidably accommodates the other end of the rod member and is fixed to the unsprung member of the vehicle are relatively displaced. In shock absorbers that generate damping force by
The rod member includes a piston on the other end side,
The cylindrical member includes an end cap on the one end side of the rod member having a through-hole through which the rod member penetrates the center and is slidable in a liquid-tight manner.
A first electrode plate is provided on the outer peripheral surface of the rod member so as to extend in the axial direction from the one end side,
Placing the first brush in the cavity facing the through hole of the end cap;
The first brush is in contact with and slides on the first electrode plate to electrically connect the rod member side and the cylindrical member side, and has a power supply function between the unsprung springs. Shock absorber provided. A second electrode plate is provided extending in the axial direction from the end cap side on the inner peripheral surface of the cylindrical member,
A second brush is disposed on the rod member so as to face the second electrode plate on the inner peripheral surface of the cylindrical member,
The second brush abuts and slides on the second electrode plate to electrically connect the rod member side and the cylindrical member side, and the electric power generated by the first brush and the first electrode plate. The shock absorber having a power supply function between the sprung and unsprung parts according to claim 1, wherein the shock absorber constitutes an electric system independent of the system . The first electrode plate and the first brush, and the second electrode plate and the second brush are slidable in the circumferential direction with the central axis of the shock absorber extending in the expansion / contraction direction as a rotation axis. The shock absorber having a power feeding function between the sprung and unsprung parts according to claim 1 or 2. A plurality of the first brushes are arranged radially with respect to the central axis of the shock absorber,
The first electrode plate is insulated and separated from the outer peripheral surface of the rod member in correspondence with the circumferential position of the first brush around the central axis of the shock absorber. A plurality are provided facing each other,
4. The power supply function between the unsprung parts according to claim 1, wherein a plurality of electric systems are formed between the first brush and the first electrode plate. 5. Shock absorber. A plurality of the second brushes are attached radially to the central axis of the shock absorber,
The second electrode plate is insulated and separated from the inner peripheral surface of the cylindrical member in correspondence with the circumferential position of the second brush around the central axis of the shock absorber. A plurality are provided facing the brush,
4. A shock absorber having a power supply function between sprung springs according to claim 2, wherein a plurality of electric systems are formed between the second brush and the second electrode plate . The angle obtained by subtracting the opening angle of the tip of each brush from the opening angle of each electrode plate viewed from the central axis of the shock absorber is equal to or greater than the total turning angle of the wheel. shock absorber having a power supply function between sprung unsprung described 5.

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