Operating knob

An operating knob to be attached to a supporting member includes an operating part and a connector. The connector is attached to the operating part and includes a fitting cylindrical portion, a stopper disposed at an inner circumferential side of the fitting cylindrical portion to protrude on a radial inside, and housing portion. When the operating part is applied with a load greater than or equal to a predetermined value from an exterior in a direction toward the supporting member in a state where a fitting portion of the supporting member is fitted into the fitting cylindrical portion, the stopper is bent from the radial inside to a direction approximately parallel to the rotation axis so as to be housed in the housing portion and the fitting cylindrical portion moves toward the supporting member along an outer circumference of the fitting portion.

CROSS REFERENCE TO RELATED APPLICATION

The present application is based on and claims priority to Japanese Patent Application No. 2007-117178 filed on Apr. 26, 2007, the contents of which are incorporated in their entirety herein by reference.

FIELD OF THE INVENTION

The present invention relates to an operating knob.

BACKGROUND OF THE INVENTION

In recent years, in order to ensure a safety of a passenger at a time where a vehicle collides, a standard is set in an in-vehicle equipment such as a car-mounted navigation apparatus and a car audio apparatus and various instruments incorporated in an instrument panel in a vehicle compartment so that an operating knob does not harm the passenger. For example, Rule No. 21 of ECE (Economic Commission for Europe) requires that the operating knob is sunk so that a protruding amount of the operating knob is within a certain amount when a load greater than or equal to 378 [N] is applied to the operating knob from an exterior in a direction toward an encoder (i.e., in a sinking direction).

U.S. Pat. No. 7,251,861 (corresponding to JP-2004-338427A) discloses an operating knob that includes a plurality of crushable connecting elements provided from a rotation axis of an encoder toward an outer circumferential side. When a load is applied to the operating knob from an exterior in the sinking direction, the crushable connecting elements are crushed, and thereby the operating knob is sunk.

In the present configuration, when a size of the operating knob becomes large, there is a possibility that the crushable connecting elements are not crushed evenly depending on a direction in which the load is applied. If the crushable connecting elements are not crushed evenly, there is a disadvantage that the crushable connecting element that has not been crushed may remain, and thereby the operating knob may not sink or the operating knob may sink obliquely.

Alternatively, JP-2001-266704A discloses an operating knob that includes shock-absorbing projections. The shock-absorbing projections are provided at a through shaft-hole portion and function as stoppers. When a load is applied to the operating knob from an exterior in the sinking direction, the shock-absorbing projections are crushed and are separated. Thereby, the operating knob is sunk.

In the present configuration, a space for housing the separated shock-absorbing projections is required in the sinking direction. In addition, there is a possibility that the separated shock-absorbing projections are caught. If the separated shock-absorbing projections are caught, also in the present case, the operating knob may not sink or the operating knob may sink obliquely.

SUMMARY OF THE INVENTION

In view of the foregoing problems, it is an object of the present invention to provide an operating knob.

According to a first aspect of the invention, an operating knob is attached to a supporting member in which an outside diameter of a fitting portion that is rotatable on a rotation axis is larger than an outside diameter of a bearing portion, and the operating knob includes an operating part having a hollow portion and a connector attached to the operating part. The connector includes a fitting cylindrical portion configured so that the fitting portion is fitted therein, a stopper disposed at an inner circumferential side of the fitting cylindrical portion to protrude on a radial inside, and housing portion. The stopper is configured to touch an end surface of the supporting member on a side of the operating part in a state where the fitting portion is fitted into the fitting cylindrical portion. The stopper is bent from the radial inside to a direction approximately parallel to the rotation axis so as to be housed in the housing portion, the fitting cylindrical portion moves toward the supporting member along an outer circumference of the fitting portion, and the hollow portion houses a portion of the supporting member on the side of the operating part when the operating part is applied with a load greater than or equal to a predetermined value from an exterior in a direction toward the supporting member in a state where the fitting portion is fitted into the fitting cylindrical portion.

In the present operating knob, the operating part and the connector integrally move toward the supporting member by bending the stopper. Thus, the operating knob can be sunk appropriately.

According to a second aspect of the invention, an operating knob is attached to a supporting member in which an outside diameter of a fitting portion that is rotatable on a rotation axis is smaller than an outside diameter of a bearing portion, and the operating knob includes an attaching part, an operating part having a hollow portion, and a connector attached to the operating part. The attaching part is configured so that the fitting portion is inserted therein and has an outside diameter larger than the outside diameter of the bearing portion. The connector includes a fitting cylindrical portion in which the attaching part is fitted, a stopper disposed at an inner circumferential side of the fitting cylindrical portion to protrude on a radial inside, and housing portion. The stopper is configured to touch an end surface of one of the supporting member and the attaching part on a side of the operating part in a state where the attaching part is attached to the fitting portion and is fitted into the fitting cylindrical portion. The stopper is bent from the radial inside to a direction approximately parallel to the rotation axis so as to be housed in the housing portion, the fitting cylindrical portion moves toward the supporting member along an outer circumference of the attaching part, and the hollow portion houses a portion of the supporting member on the side of the operating part when the operating part is applied with a load greater than or equal to a predetermined value from an exterior in a direction toward the supporting member in a state where the attaching part is attached to the fitting portion and is fitted into the fitting cylindrical portion.

In the present operating knob, the operating part and the connector integrally move toward the supporting member by bending the stopper. Thus, the operating knob can be sunk appropriately.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

First Embodiment

An operating knob1according to a first embodiment of the invention will be suitably used for a navigation apparatus provided in a vehicle. The operating knob1will be described with reference toFIG. 1AtoFIG. 3. The operating knob1includes an operating part2and a connector3. The operating part2is made of resin and has a cap shape. The operating part2has a hollow portion5that opens on a side of an encoder4(i.e., supporting member). The operating part2further includes a plurality of (e.g., eight) bosses6. The bosses6are arranged evenly along a circumferential direction and extend in a direction approximately parallel to a rotation axis11of the encoder4shown inFIG. 2.

The connector3is made of a resin having a high toughness, for example, polycarbonate resin. The connector3is formed by a combination of a contact surface portion7having an approximately circular plate shape and a fitting cylindrical portion8having an approximately cylindrical shape. The contact surface portion7has a plurality of (e.g., eight) insertion holes9in which the plurality of bosses6formed at the operating part2is inserted respectively. On an outer circumferential side of the fitting cylindrical portion8, a plurality of (e.g., eight) ribs10(reinforced elements) for ensuring the strength of the fitting cylindrical portion8is disposed across the contact surface portion7, and the ribs10are arranged evenly along the circumferential direction. In the present case, each of the ribs10is located at a middle portion of two insertion holes9provided at the contact surface portion7.

The fitting cylindrical portion8extends in a direction approximately parallel to the rotation axis II. At a halfway of an inner circumferential side of the fitting cylindrical portion8in the extending direction, two stoppers11aand11bthat protrude on a radial inside are arranged evenly in the circumferential direction. That is, the stoppers11aand11bare arranged to have an angle of 180 degrees therebetween. A portion from a position at which the stoppers11aand11bare provided to the contact surface portion7expands outwardly. A space generated due to the expansion provides housing portions12aand12b. When the stoppers11aand11bare bent from the radial inside to a direction approximately parallel to the rotation axis II, the bent stoppers11aand11bare housed in the housing portion12aand12b. In addition, the fitting cylindrical portion8has two slits13aand13b. The stoppers11aand11bare provided at portions extending from portions at which the slits13aand13bare provided in a direction approximately parallel to the rotation axis II.

The encoder4is formed by a combination of a fitting portion14that is rotatable on the rotation axis II and a bearing portion15that holds the fitting portion14to be rotatable. Teeth are formed on the whole outer circumference of the fitting portion14, and one end side of the bearing portion15is fixed, for example, to a printed board16. A spring17is made of metal. The spring17has a discontinuous portion and has a ring shape that has an inside diameter equal to an outside diameter of the fitting cylindrical portion8of the connector3. In view of the circumstance that the connector3is made of resin, the spring17is disposed for preventing a loose of a fit (i.e., idle) between the fitting cylindrical portion8of the connector3and the fitting portion14of the encoder4, which may be generated due to a thermal contraction or a thermal expansion of the resin.

In the components configured in this manner, after the bosses6of the operating part2are inserted into the insertion holes9of the connector3, end portions of the bosses6(i.e., portions protruding from the contact surface portion7) are heated, and then the bosses6are joined to the contact surface portion7by welding. Thereby, the operating part2is attached to the connector3to configurate the operating knob1. In addition, the spring17is disposed at the outer circumference of the fitting cylindrical portion8of the connector3and the fitting portion14of the encoder4is fitted into the fitting cylindrical portion8of the connector3. Thereby, the operating knob1is (the operating part2and the connector3are integrally) attached to the encoder4.

Because the fitting portion14of the encoder4is fitted into the fitting cylindrical porting8of the connector3so that peaks of the teeth formed at the outer circumference of the fitting portion14are crushed, the fitting portion14of the encoder4is firmly joined to the connector3. Thereby, the fitting portion14of the encoder4rotates following a rotation of the operating knob1. When the fitting portion14of the encoder4is fitted into the fitting cylindrical portion8appropriately, an end surface14aof the fitting portion14touches the stoppers11aand11b.

An outside diameter (“r1” inFIG. 3) of the fitting portion14of the encoder4is larger than an outside diameter (“r2” inFIG. 3) of the bearing portion15of the encoder4. Thus, when the operating knob1sinks, an end side of the fitting cylindrical portion8does not touch the bearing portion15of the encoder4. That is, a movement of the fitting cylindrical portion8is not disturbed. Furthermore, an inside diameter (“R” inFIG. 3) of the hollow portion5of the operating part2is larger than the outside diameter of the fitting portion14of the encoder4. Thus, when the operating knob1sinks, the hollow portion5of the operating part2houses the fitting portion14of the encoder4.

When a load greater than or equal to a predetermined value is applied to the operating knob1from an exterior in a direction toward the encoder4, i.e., a sinking direction shown by the arrow P inFIG. 1B, a stress is applied to the operating part2and the connector3so as to move integrally in the sinking direction. Then, a pressure is applied to the stoppers11aand11b, which protrude on the radial inside, from the end surface14aof the fitting portion14of the encoder4as a reaction of the stress. When the load applied to the operating knob1exceeds the predetermined value and the pressure applied to the stoppers11aand11bfrom the end surface14aof the fitting portion14of the encoder4exceeds the predetermined value, the stoppers11aand11b, which protrude on the radial inside, are bent in a direction that is approximately parallel to the rotation axis II and that is an approximately opposite to the encoder4. Thereby, the stoppers11aand11bare housed in the housing portion12aand12b(see the arrows S1and S2inFIG. 1B).

Thus, the fitting cylindrical portion8of the connector3moves along the outer circumference of the fitting portion14of the encoder4and the operating part2and the connector3integrally move toward the encoder4. As a result, as shown inFIG. 1B, the operating knob1sinks until an end8aof the fitting cylindrical portion8touches a touching surface15aof the bearing portion15of the encoder4. At this time, the stoppers11aand11bbent from the radial inside to the direction approximately parallel to the rotation axis II remain without being separated. Thus, the stoppers11aand11band an inner wall of the fitting cylindrical portion8function as guides, and thereby the operating knob1sinks straight in the sinking direction without a generation of a rattle. In addition, because the ribs10are arranged evenly at the outer circumference of the fitting cylindrical portion8, the fitting cylindrical portion8is prevented from being broken or deformed during the operating knob1is sinking, and a generation of a rattle is restricted. Thus, the operating knob1sinks straight also due to the presence of the ribs10.

A strength of this crushable structure for sinking the operating knob1can be determined freely by changing a thickness (a dimension in the sinking direction), a width (a dimension in the circumferential direction), a length (a dimension in the radial direction) and the number of the stoppers11aand11b.

As described above, when the load greater than or equal to the predetermined value is applied to the operating knob1from the exterior in the sinking direction in a state where the operating knob1is attached to the encoder4, the operating part2and the connector3integrally move toward the encoder4while bending the stoppers11aand11bprovided on the inner circumferential side of the fitting cylindrical portion8. Thus, even when the size of the operating knob1becomes large, the operating knob can be sunk appropriately.

In addition, the stoppers11aand11bbent from the radial inside to the direction approximately parallel to the rotation axis11are housed in the housing portion12aand12bprovided at positions not to disturb the movement of the fitting cylindrical portion8along the outer circumference of the fitting portion14in the axial direction. Thus, a space in the sinking direction for housing separated shock-absorbing projections is not required. In addition, because the stoppers11aand11bare configured to remain without being separated, the stoppers11aand11band the inner wall of the fitting cylindrical portion8can function as the guides. Thereby, a generation of a rattle in the sinking direction is restricted and the operating knob1can be sunk straight with a high degree of certainty.

Furthermore, because the ribs10for ensuring the strength of the fitting cylindrical portion8are formed on the outer circumferential side of the fitting cylindrical portion8, the fitting cylindrical portion8is prevented from being broken or deformed during the operating knob1is sinking, and a generation of a rattle in the sinking direction is restricted. As a result, the operating knob1can be sunk straight also due to the presence of the ribs10. In addition, because the stoppers11aand11bare arranged evenly in the circumferential direction, the load applied to the operating part2from the exterior can be transmitted to the encoder4evenly through the stoppers11aand11b.

Furthermore, the stoppers11aand11bare provided at the portions extending from the portions at which the slits13aand13bare provided in the direction approximately parallel to the rotation axis II. Thus, the load applied from the exterior in the sinking direction function as a stress toward the outside in a diagonal direction of a direction that connects the portions of the fitting cylindrical portion8at which the slits13aand13bare provided. In contrast, the load function as a stress toward an inside in the direction that connects the portions of the fitting cylindrical portion8at which the slits13aand13bare provided. Thus, the load applied to the operating part2from the exterior can be effectively transmitted to the encoder4through the stoppers11aand11b.

Second Embodiment

Next, an operating knob1according to a second embodiment of the invention will be described with reference toFIG. 4and theFIG. 5. A description of the same parts as the above-described first embodiment is omitted and different parts will be described. The operating knob1shown inFIG. 2is attached to the encoder4in which the outside diameter of the fitting portion14is larger than the outside diameter of the bearing portion15. In contrast, the operating knob1shown inFIG. 4is attached to an encoder22in which an outside diameter of a fitting portion is smaller than an outside diameter of a bearing portion.

As shown inFIG. 4, the operating knob1includes an attaching part21in addition to the operating part2and the connector3. The attaching part21has a fitting hole21ahaving a concave shape, and the attaching part21is attached to a fitting portion23of the encoder22by inserting the fitting portion23of the encoder22into the fitting hole21a. In the present case, an outside diameter (“r11” shown inFIG. 5) of the fitting portion23of the encoder22is smaller than an outside diameter (“r12” shown inFIG. 5) of a bearing portion24of the encoder22. However, an outside diameter (“r13” shown inFIG. 5) of the attaching part21attached to the fitting portion23of the encoder22is larger than the outside diameter of the bearing potion24of the encoder22. InFIG. 4, a rotation axis of the encoder22is shown as an axis IV.

In the present case, the fitting portion23of the encoder22is inserted into the fitting hole21aof the attaching part21and the attaching part21is fitted into the fitting cylindrical portion8of the connector3, and thereby the operating knob1is attached to the encoder22. Thus, apparently, it has an aspect same as an aspect of the operating knob1inFIG. 2attached to the encoder4. The fitting portion23of the encoder22is inserted into the fitting hole21aof the attaching part21in such a manner that peaks of teeth formed at an outer circumference of the fitting portion23of the encoder22are crushed, and the attaching part21is fitted into the fitting cylindrical portion8of the connector3in such a manner that peaks of teeth formed at an outer circumference of the attaching part21are crushed. Thus, the fitting portion23of the encoder22is firmly joined to the connector3through the attaching part21. Thereby, the fitting portion23of the encoder22rotates following the rotation of the operating knob1. When the fitting portion23of the encoder22is appropriately fitted into the fitting cylindrical portion8of the connector3through the attaching part21, an end surface21aof the attaching part21btouches the stoppers11aand11b.

As described above, in the present embodiment, the operating knob1shown inFIG. 4is attached to the encoder22, in which the outside diameter of the fitting portion23is smaller than the outside diameter of the bearing portion24, through the attaching part21. The operating knob1shown inFIG. 4can have an effect similar to that of the operating knob1shown inFIG. 2.

Other Embodiments

For example, an application of the operating knob1is not limited to the navigation apparatus provided in the vehicle. Alternatively, the operating knob1may be used for an operating knob in an in-vehicle equipment such as a car audio apparatus and various instruments incorporated in an instrument panel in a vehicle compartment.

The fitting portions14and23of the encoder may be made of metal. The cross-sectional shapes of the fitting portions14and23of the encoder and the cross-sectional shape of the attaching part21in a direction perpendicular to the rotation axis II or IV may be D-cut shape as long as a joint strength of the fitting portion14of the encoder4with respect to the connector3in the first embodiment, and a joint strength of the fitting portion23of the encoder22with respect to the attaching part21and a joint strength of the attaching part21with respect to the connector3in the second embodiment are ensured sufficiently.

The number of the stopper provided in the inner circumferential side of the fitting cylindrical portion8of the connector3may be one or more than two. When more than two stoppers are provided, the stoppers may be arranged evenly in the circumferential direction.

The number of the ribs10provided on the outer circumferential side of the fitting cylindrical portion8of the connector3may be less than eight or more than eight as long as a strength for restricting a generation of a rattle at a time where the operating part2and the connector3integrally move toward the encoder4or23can be ensured. In the present case, the ribs10may be arranged evenly in the circumferential direction.