Patent Publication Number: US-2023140066-A1

Title: Mechanical knob apparatus capable of push and rotation operations

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Pat. Application No. 10-2021-0150073, filed on Nov. 3, 2021, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     Field of the Invention 
     The present invention relates to a mechanical knob, and more specifically, to a mechanical knob apparatus having a structure capable of both a push operation and a rotation operation for adjusting functions of devices in a vehicle. 
     Discussion of Related Art 
     A tact switch is generally used for a push operation of a button. Since a lower portion of the button comes into contact with or is close to the tact switch, when the button is pressed, the tact switch is pressed to implement the push operation. In addition, encoders from conventional parts vendors (ALPS, PANASONIC, and the like) are often used to implement the rotation operation of the knob. 
     As described above, the tact switch may perform only the push operation of the button, and the encoder may perform only the rotation operation of the knob, thereby degrading the degree of freedom in design. In particular, in the encoder, it is difficult to tune the torque and detent (the number of rotations) of the knob, and the material cost is high. 
     In addition, there are mechanical knobs manufactured by designing mechanical structures according to specific demands. However, even in this case, the knob has a structure in which only a simple rotation operation is possible and requires many parts to implement the operation, and thus has disadvantages of more difficult assembly and a high price, and a problem that the operation feeling is changed by a deviation of the shape of a spring when a leaf spring is applied. 
     SUMMARY OF THE INVENTION 
     In recent vehicle interiors, conventional push buttons have been gradually disappearing, and all functions tend to be performed by a button of a knob. Accordingly, a push operation and a rotation operation should be implemented together in the knob for a vehicle. For example, operation knobs of air conditioners or audio/visual (AV) devices should perform functions such as power on/off and mode selection by the push operation, and perform functions such as temperature control, volume, and tuning by the rotation operation. However, the knob products supplied by conventional parts vendors may perform only the rotation or push operation, and the degree of freedom in design is degraded. 
     Accordingly, the present invention proposes a mechanical knob having a structure in which the knob may be designed and tuned according to various design conditions (size and the like of the knob) without restriction conditions such as a size, height, and the like of the knob, the push and rotation operations of the knob may be performed, and many parts are not required unlike the conventional mechanical knobs. 
     According to one aspect of the present invention, there is provided a mechanical knob apparatus capable of push and rotation operations, the mechanical knob apparatus including: a dial configured to transmit a force at which a user rotates or presses a knob to perform the rotation or push operation of the knob as an exterior part of the knob exposed to an outside; a push operation unit coupled to the dial through a radial bearing to perform the push operation; and a rotation operation unit coupled to the dial to perform both the push operation and the rotation operation. 
     In addition, according to another aspect of the present invention, there is provided a mechanical knob apparatus capable of push and rotation operations, the mechanical knob apparatus including: a printed circuit board (PCB) equipped with a tact switch and a photosensor; a dial configured to transmit a force at which a user rotates or presses a knob to perform the rotation or push operation of the knob as an exterior part of the knob exposed to an outside; a means coupled to the dial to push the tact switch assembled to the PCB; a detent housing having one end coupled to the dial, configured to accommodate a tact switch push unit therein, formed with an unevenness guide over a circumference of an inner diameter, and formed with a plurality of slits over a circumference of the other end to detect an amount of rotation of the dial in conjunction with the photosensor; a detent elastically coupled to the unevenness guide of the detent housing and configured to radially perform an elastic movement upon the rotation operation of the dial and the detent housing; and a knob housing coupled to the detent housing and configured to accommodate the detent therein. 
     Configurations and operations of the present invention will become clearer through specific embodiments described below together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing exemplary embodiments thereof in detail with reference to the accompanying drawings, in which: 
         FIG.  1    is an exploded view of a mechanical knob apparatus according to an embodiment of the present invention; 
         FIG.  2    is a cross-sectional view of an assembled state; 
         FIG.  3    is an exterior perspective view; 
         FIG.  4    is an exploded perspective view of components of a knob operation unit; 
         FIG.  5    is an exploded perspective view of components of a knob rotation implementation unit; 
         FIG.  6    is a top perspective view of a knob housing  11 ; 
         FIGS.  7 A and  7 B  are partial cross-sectional views of the knob housing  11 ; 
         FIGS.  8 A and  8 B  are perspective views showing that a detent housing  8  is assembled to the knob housing  11 ; 
         FIG.  9    is a perspective view of the detent housing  8  viewed from a bottom; 
         FIG.  10    is a longitudinal cross-sectional view showing a specific structure of a decent  9  installed in the knob housing  11 ; 
         FIGS.  11 A and  11 B  are each a perspective view and a longitudinal cross-sectional view for describing a structure for preventing knob wobble; 
         FIG.  12    is a cross-sectional view of an assembled knob apparatus laterally taken from a body portion of an LCD housing  4 ; 
         FIG.  13    is a cross-sectional view of a lowermost end of the LCD housing  4  laterally cut; and 
         FIG.  14    is a view for describing a structure of implementing in which a detent count upon rotation operation of the knob apparatus. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Advantages and features of the present invention and methods of achieving them will be made clear from exemplary embodiments described in detail below with reference to the accompanying drawings. However, the present invention is not limited to embodiments disclosed below but may be implemented in various different forms. Only these embodiments are provided so that the disclosure of the present invention will be thorough and complete and will fully convey the scope of the present invention to those skilled in the art to which the present invention pertains, and the present invention is defined by the description of the claims. In addition, the terms used in this specification are to describe embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless otherwise specified in the phrase. In addition, the terms ‘comprise, comprising, and the like’ as used in the specification are used as the meaning that does not preclude the presence or addition of one or more other components, steps, operations, and/or elements other than the stated components, steps, operations, and/or elements. 
     Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of embodiments, when a detailed description of a related known configuration or function may obscure the gist of the present invention, a detailed description thereof will be omitted. 
       FIG.  1    is an exploded view of a mechanical knob apparatus according to an embodiment of the present invention. In addition,  FIG.  2    is a cross-sectional view of an assembled state, and  FIG.  3    is an exterior perspective view. Each component will be described with reference to  FIGS.  1 ,  2  and  3   . 
     Knob decoration  1 : An exterior design part that functions to prevent foreign substances from being introduced into a gap between a knob  6  and a liquid crystal display (LCD)  2  and plays a role in improving exterior quality as a structure assembled to an upper portion of the LCD  2 . 
     LCD  2 : Displays necessary environmental information in a vehicle (vehicle temperature, sound volume, and the like) as a flat-panel display. 
     LCD housing  4 : A part that functions to fix the LCD  2  using a double-sided foam tape  3  or the like, and comes into contact with a tact switch (not shown) assembled to a printed circuit board (PCB)  13  to push the tact switch. The LCD housing  4  has a hollow cylindrical shape having a partially empty inside so that an LCD cable (not shown) to be bonded to the PCB  13  may pass therethrough. The LCD housing  4  is coupled to a dial  6  to perform a push operation. 
     Dial  6 : An exterior part of the knob exposed to the outside, and a medium that transmits a force at which a driver (user) holds or presses the knob to perform the rotation or push operation of the knob while functioning as an indoor interior. 
     Detent housing  8 : Engaged with a detent  9  by coupling one end (upper end in  FIG.  1   ) of the cylindrical housing to the dial  6  and forming a plurality of floor/valley-shaped unevenness guides inside the other end (lower end in  FIG.  1   ). In addition, a plurality of slits are formed at the other end over a circumference to detect the amount of rotation of the knob in conjunction with a photosensor. The detent housing  8  has a structure in which both a rotation operation according to the rotation of the dial  6  and a push operation according to the push of the LCD housing  4  and the dial  6  are possible. The detent housing  8  is positioned inside a front panel  7  and assembled with the dial  6  positioned outside. 
     Radial bearing  5 : Assembled between the LCD housing  4  and the dial  6  in a method such as force-fitting or the like. The LCD housing  4  may perform only the push operation, and the detent housing  8  may perform both the push and rotation operations by the radial bearing  5 . 
     Knob housing  11 : One end is fixed to the PCB  13  and the other end is coupled to the detent housing  8 , and the detent  9  engaged with the unevenness guide of the detent housing  8  is accommodated in the knob housing  11 . The knob housing  11  is coupled to the detent housing  8  through a ball bearing  10  to rotate according to the rotation of the detent housing  8 . 
     Detent  9  and spring  901 : Assembled inside the knob housing  11 , the detent  9  radially performs an elastic motion by the tension of the spring  901  upon the rotation operations of the dial  6  and the detent housing  8 . The detent or the amount of rotation of the dial  6  corresponds to the number of clicks (contact and separation) between the unevenness guide of the detent housing  8  and the detent  9 . In addition, the radial movement operation by the detent  9  and the elasticity of the spring  901  generates the operation feeling when the dial  6  is rotated. 
     PCB  13 : A tact switch ( 131  in  FIG.  2   ) for the push operation of the knob and a photosensor ( 132  in  FIG.  2   ) for generating a detent detection signal upon the rotation operation of the knob are mounted on the PCB  13 . 
     Front panel  7 : An exterior part that is assembled to a dashboard or center fascia of a driver seat and exposed toward a driver (forward). 
     Screw  12 : A fastening means for coupling the knob housing  11  to the front panel  7 . 
     Back cover  14 : A rear side exterior part of the entire structure of the knob apparatus. 
     Hereinafter, the entire structure and operation of the knob apparatus capable of the push and rotation operations according to an embodiment of the present invention will be described in detail. 
       FIG.  4    is an exploded perspective view of a knob operation unit configuring an exterior of the knob apparatus among components shown in  FIG.  1   . The knob operation unit is a part exposed to the outside of the front panel  7 . A structure of the knob operation unit will be described through an assembly method of the knob operation unit. 
     The knob decoration  1  and the LCD  2  may be coupled by force-fitting, or by a double-sided tape (not shown). The knob decoration  1  and the LCD  2  are portions exposed to the user (driver) and directly operated by the user. 
     The LCD  2  and the LCD housing  4  are assembled with the sponge-series double-sided foam tape  3  (the elasticity of the foam suppresses the occurrence of a screen distortion (such as ‘Mura’, blemish, etc.) occurring in the screen when the user pushes the LCD  2 .). The LCD housing  4  has a hollow cylindrical structure having an empty central portion, and a cable  201  of the LCD  2  passes through the hollow and then is bonded to the PCB  13 . In addition, a terminal  401  of the LCD housing  4  is installed to come into contact with or be close to the tact switch  131  mounted on the PCB  13  to press the tact switch  13  when the user pushes the knob decoration  1  or the LCD  2 . 
     Each of the LCD housing  4 , the radial bearing  5 , and the dial  6  is assembled by force-fitting. In other words, as shown in  FIG.  4   , an outer diameter of the LCD housing  4  is force-fitted into an inner diameter of the radial bearing  5 , and an inner diameter of the dial  6  is force-fitted into an outer diameter of the radial bearing  5 . Accordingly, since the LCD housing  4  and the dial  6  are axially fixed, when the LCD housing  4  is pushed, the dial  6  also performs the push operation accordingly (of course, the terminal  401  of the LCD housing presses the tact switch), but the rotation operation of the dial  6  is possible independently with respect to the LCD housing  4  in a circumferential direction. 
       FIG.  5    to  8 B show a rotation implementation unit of the knob apparatus. The rotation implementation unit is a portion that is positioned inside the front panel  7  and is not exposed to the outside. A structure of the knob rotation implementation unit will be described through the assembly method of the knob rotation implementation unit. 
       FIG.  5    shows components of the rotation implementation unit. The detent housing  8  is coupled to the knob housing  11  through the ball bearing  10 , and a pair of detents  9  are coupled to the unevenness guide inside the detent housing  8 , which will be described below. In addition, the ball bearing  10  is fitted into an outer diameter of the knob housing  11 , and the pair of detents  9  are installed to protrude radially together with each spring  901  inside the knob housing  11 . The ball bearing  10  has a form in which a plurality of balls  101  are rotatably embedded in a ring toward the detent housing  8 . 
       FIG.  6    shows that the ball bearing  10  is assembled on the outer diameter of the knob housing  11  and the pair of detents  9  are installed to protrude from the inside to the outside. The ring-shaped ball bearing  10  is fixed by two hooks  111  after being fitted onto the outer diameter of the knob housing  11 . In addition, it can be seen that a tip of the detent  9  protrudes through an opening  112  formed in the outer diameter of the knob housing  11  (a coupling structure of the detent  9  and the spring  901  will be described below.). A panel fastening unit  113  fixed to the front panel  7  by the screw ( 12  in  FIG.  1   ) is formed in an outermost portion of the knob housing  11 . 
       FIGS.  7 A and  7 B  are cross-sectional views of a state in which the detent  9  is assembled to the knob housing  11 . First, the detent  9  is inserted into the spring  901  and is composed of a body portion  902  positioned inside the knob housing  11 , a tip portion  903  exposed to the outside of the outer diameter of the knob housing  11 , and a locking projection  904  formed on the body portion  902  so as not to be separated to the outside of the outer diameter of the knob housing  11 . In addition, a pocket  114  into which the body portion  902  of the detent  9  and the spring  901  enter is formed inside the knob housing  11 , and the opening  112  allowing the tip portion  903  of the detent  9  to be exposed is formed in the outer diameter of the knob housing  11 . With this structure, as shown in  FIGS.  7 A and  7 B , the detent  9  is inserted into the pocket  114  of the knob housing  11  and the tip portion  903  is exposed to the outside of the opening  112 . In order to prevent the body portion  902  of the detent  9  from being separated to the outside of the opening  112 , the locking projection  904  is locked to a boundary surface of the opening  112  of the knob housing  11  (see  FIG.  7 B ). 
       FIGS.  8 A and  8 B  show that the detent housing  8  is assembled to the knob housing  11  in which the ball bearing  10  and the detent  9  are assembled as described above. The inner diameter of the detent housing  8  is fitted into and assembled to the outer diameter of the knob housing  11 , and thus one end of the detent housing  8  may come into contact with the ball bearing  10  to rotate smoothly, and the tip portion  903  of the detent  9  is coupled to the unevenness guide (to be described below) formed inside the detent  9  to perform a click operation according to the rotation of the detent housing  8 . When the detent housing  8  rotates in a click manner, light of the photosensor  132  of the PCB  13  may be blocked by/passed through a slit  802  (to be described below) of the detent housing  8  to detect the amount of rotation. As shown in  FIG.  8 A , after being inserted into the outer diameter of the knob housing  11 , the detent housing  8  is fastened by four fixing hooks  115  formed at the outermost portion of the knob housing  11 . The number and shape of the hooks  115  may be changed depending on the overall design, size, and the like of the knob apparatus. In addition, as shown in  FIG.  8 B , a contact portion  116  of the detent housing  8  and the fixing hook  115  of the knob housing  11  at least may come into point contact with each other so that the rotation operation can be smoothly performed in a state in which the detent housing  8  is fastened. 
     As described above, the panel fastening unit  113  of the knob housing  11  in which the ball bearing  10 , the detent  9 , and the detent housing  9  are assembled is fastened and assembled to the front panel  7  with the screw  12 . In addition, as described earlier (see  FIG.  2   ), the dial  6  is coupled to the detent housing  8  through the front panel  7 . 
       FIGS.  9  and  10    are views for describing the detent count, rotation resistance, and operation feeling of the dial  6  (and the detent housing  8  accordingly).  FIG.  9    is a view showing the detent housing  8  viewed from the bottom, that is, viewed from the right in  FIG.  1   , and shows a coupling relationship between the ball bearing  10  and the detent  9  fitted into the knob housing  11  (not shown). In addition,  FIG.  10    is a longitudinal cross-sectional view showing a coupling structure of the detent  9  installed in the knob housing  11  and an unevenness guide  801  of the detent housing  8 . 
     A plurality of unevenness guides  801  are formed on an inner surface of the detent housing  8 . Concave and convex surfaces of the unevenness guide  801  are axially recessed and surfaces thereof are formed to be round, and as shown in  FIGS.  7 A and  7 B , the tip portion  903  of the detent  9  is positioned to protrude radially at a 180° position with respect to the outer diameter of the knob housing  11 , and thus, the tip portion  903  of the detent  9  performs the click operation by moving in and out of the unevenness guide  801  when the detent housing  8  is rotated. When the number of clicks is counted (e.g., when the number of times of light blocking of the photosensor by the slit of the detent housing  8  is used), the detent of the detent housing  8  may be known. Since the detent housing  8  rotates together with the dial  6 , when the user turns the dial  6 , the amount of rotation or detent of the dial  6  may be known by a reciprocal motion of the detent  9  with respect to the unevenness guide  801  (to this end, the photosensor  132  assembled to the PCB  13  may be used). A micro control unit (MCU) calculates a control amount corresponding to a degree to which the user turns the dial  6  by processing the detent. 
     In addition, since the click operation of the detent  9  is performed by the spring  901 , an elastic force (tension) of the spring  901  with respect to the unevenness guide  801  directly generates the rotation resistance and operation feeling when the dial  6  rotates. The rotation resistance and the operation feeling of the dial  6  are adjustable according to changes in heights and widths of the floor/valley (concave surface/convex surface) of the unevenness guide  801  together with the spring  901 , and the operation feeling can be tuned by appropriately adjusting these parameters according to a buyer’s request to tune the operation feeling. Of course, the type (coil spring, leaf spring, or the like), material, number of turns, outer diameter, and the like of the spring  901  are also one of parameters necessary for adjusting the operation feeling. 
     In addition, in order to minimize a ghost flow (slightly idle feeling when clicking) upon operation of the dial, the shapes of the concave surface/convex surface of the unevenness guide  801  of the detent housing  8  and the shape of the tip portion  903  of the detent  9  should be matched one-to-one. In addition, in order to reduce a frictional force between the unevenness guide  801  and the tip portion  903  of the detent when the dial  6  is rotated, a contact area between a surface other than the concave surface of the unevenness guide  801  and the tip portion  903  of the detent may be as small as possible (ideally, point contact). 
       FIGS.  11 A and  11 B  are a perspective view and a longitudinal cross-sectional view for describing a structure for preventing knob wobble. 
     The detent housing  8  is a rotating body, and coupled to the knob housing  11 , which is a fixed body, through the ball bearing  10  therebetween. In addition, the dial  6  is a rotating body, and coupled to the LCD housing  4 , which is a fixed body, through the radial bearing  5  therebetween. Accordingly, it comes into point contact with the ball bearing  10  and comes into surface contact with (is force-fitted into) the radial bearing  5 . In addition, in terms of an overall structure, since the ball bearing  10  is positioned at the bottom of the knob structure and the radial bearing  5  is positioned at the top thereof, a wobble other than the torque by the rotation of the knob is prevented. 
     The push operation of the knob will be described with reference to  FIGS.  12  and  13   .  FIG.  12    is a cross-sectional view of the assembled knob apparatus laterally taken from the body portion of the LCD housing  4 , and  FIG.  13    is a cross-sectional view of a lowermost end of the LCD housing  4 . 
     As described above, since the dial  6  is in a state of being force-fitted into the LCD housing  4  via the radial bearing  5 , and the LCD  2  and the LCD housing  4  are fixed by the double-sided foam tape  3 , when either the dial  6  or the LCD  2  is pushed, the dial  6 , the LCD  2 , and the LCD housing  4  axially move together (however, when the dial  6  is rotated, only the detent housing  8  rotates due to the characteristics of the radial bearing  5 .). 
     As a structure of ensuring the push operation, the LCD housing  4  and the knob housing  11  are formed with a slide structure for the push operation in the axial direction. Referring to  FIG.  12   , four guide protrusions  401  are axially formed long on the outer diameter of the LCD housing  4 , and four rails  117  are axially formed long on the inner diameter of the knob housing  11  coupled to the LCD housing  4  and coupled to the guide protrusions  401 . Accordingly, the LCD housing  4  is prevented from being separated upon the push operation with respect to the knob housing  11  and smoothly operated. 
     In addition, a cross rib  402  positioned at the lowermost end of the LCD housing  4  and pressing the tact switch  131  mounted on the PCB  13  will be described with reference to  FIG.  13   . In other words, when the LCD  2  or the dial  6  of the knob apparatus is pressed, the cross rib  402  at the lowermost end of the LCD housing  4  operates the tact switch  131  of the PCB  13  as the LCD housing  4  is pushed. Accordingly, the MCU executes functions (e.g., power on/off, mode selection, and the like) given to the corresponding tact switch. 
       FIG.  14    is a view for describing a structure of implementing the detent count upon the rotation operation of the knob apparatus. A plurality of slits  802  are formed in the lower portion of the detent housing  8 , that is, a portion coming into contact with the PCB  13  in the circumferential direction. The slits  802  are configured to pass between a light emitting portion and a light receiving portion of the photosensor  132  to allow light to pass or block between the light emitting portion and the light receiving portion of the photosensor  132  when the detent housing  8  is rotated. It is possible to recognize the detent or the amount of rotation of the knob apparatus by counting the number of passing and blocking of this light, and execute a function coded as a program correspondingly. 
     Meanwhile, in order to prevent the push operation of the knob apparatus from affecting the detent count, a distance (‘H1’ shown in  FIG.  14   ) from the PCB  13  to a cut position of the slit  802  of the detent housing  8  should be set greater than a distance H2 from the PCB  13  to a position of a light beam of the photosensor  132 . This is because the slit  802  does not affect the operation of blocking or passing light of the photosensor  132  even when the detent housing  8  moves down by the push operation of the knob apparatus. 
     According to the present invention, it is possible to perform rotation and push operations of a knob itself, improve a torque of the knob, and improve performance because a difference in an operation feeling of the knob due to a deviation between parts does not occur when the knob is mass produced. In addition, it is possible to reduce costs (reduce a mold cost and a material cost) when compared to asking conventional encoder vendors to develop new knobs and improve the degree of freedom in design. Since the requirements for design and operating conditions of the knob, the operation feeling of the knob, and the like are different for each customer in the field, the structure of the knob according to the present invention can quickly and easily respond to these requirements. 
     Until now, although the present invention has been described in detail through the exemplary embodiments of the present invention, those skilled in the art to which the present invention pertains will understand that the present invention may be embodied in specific forms different from the contents disclosed in this specification without changing the technical spirit or essential features of the present invention. 
     As described above, it should be understood that the above-described embodiments are illustrative and not restrictive in all respects. In addition, the scope of the present invention is defined by the claims to be described below rather than the above detailed description, and all changed or modified forms derived from the claims and their equivalent concepts should be interpreted as being included in the technical scope of the present invention.