CN112050266A

CN112050266A - Gas valve, cooker comprising gas valve and feedback method of firepower change of cooker

Info

Publication number: CN112050266A
Application number: CN202010996458.2A
Authority: CN
Inventors: 苏慧玲; 俞瑜; 严力峰
Original assignee: Ningbo Fotile Kitchen Ware Co Ltd
Current assignee: Ningbo Fotile Kitchen Ware Co Ltd
Priority date: 2020-09-21
Filing date: 2020-09-21
Publication date: 2020-12-08
Anticipated expiration: 2040-09-21
Also published as: CN112050266B

Abstract

The invention discloses a gas valve, a stove comprising the gas valve and a feedback method of fire change of the stove, and comprises a gas valve body and a valve rod, wherein the valve rod can rotate relative to the valve body, the valve rod is provided with a positioning end positioned on the valve body, the valve body comprises a rotation limiting channel, the rotation limiting channel receives and limits the positioning end when the valve rod rotates, and the channel height of the rotation limiting channel changes along with the change of the rotation angle of the valve rod. This gas valve can make the valve rod take place rotatoryly with modes such as rotating the knob at the user, when adjusting the firepower size, carries on spacingly and the guide to the location end of valve rod through the rotatory spacing passageway that sets up on the valve body, makes the height of valve rod and knob correspond the change according to the rotation angle change of valve rod, can directly feed back to the user through the altitude variation of valve rod, improves the user to the cognitive directly perceived degree of firepower size change.

Description

Gas valve, cooker comprising gas valve and feedback method of firepower change of cooker

Technical Field

The invention relates to a gas valve, a cooker comprising the gas valve and a feedback method of the firepower change of the cooker.

Background

In the prior art, a user can change the firepower of the cooker by rotating a gas knob. However, when the user changes the gas knob angle in a rotating manner, the user is difficult to accurately and directly feel the specific degree of the change of the gas knob angle, so that the user is difficult to intuitively feel the degree of the change of the fire power of the cooking range, and further the user is easy to cause that the fire power of the cooking range cannot be switched to the actually desired size, so that the cooking quality is reduced, and the use experience of the user is influenced.

Disclosure of Invention

The invention aims to overcome the defect that in the prior art, the user is not aware of the firepower change degree of a cooker, and provides a gas valve, the cooker comprising the gas valve and a feedback method of the firepower change of the cooker.

The invention solves the technical problems through the following technical scheme:

the utility model provides a gas valve, its includes valve body and valve rod, the valve rod can be relative the valve body is rotatory, the valve rod have be located the location end of valve body, the valve body includes rotatory spacing passageway, rotatory spacing passageway is in the valve rod holds and spacing when rotatory the location end, the passageway height of rotatory spacing passageway is followed the rotation angle of valve rod changes and changes.

This gas valve can make the valve rod take place rotatoryly in modes such as the rotation knob at the user, when adjusting the firepower size, carry out spacing and guide to the location end of valve rod through the rotatory spacing passageway that sets up on the valve body, the rotation angle change that highly can be according to the valve rod of messenger valve rod and knob corresponds the change, so that the firepower size of gas can also give the user through the altitude variation direct feedback of valve rod, in order to further improve the cognition of user to the change of firepower size, when effectively improving the rotatory valve rod of user in order to adjust the firepower, the degree directly perceived to the firepower size of cooking utensils.

Preferably, the gas valve changes the output gas quantity of the gas valve based on the rotation angle of the valve rod, and the channel height of the rotation limiting channel changes along with the change of the output gas quantity of the gas valve.

Above-mentioned structural setting changes along with the change of the output gas volume of gas valve through the passageway height that makes rotatory spacing passageway to make the firepower size that the user adjusted through rotatory valve rod and the altitude variation phase-match of valve rod, further improve the user to the perceived degree of intuition of firepower size of cooking utensils.

Preferably, the passage height of the rotation restricting passage increases as the output gas amount of the gas valve increases.

Above-mentioned structural setting makes the valve rod feed back gas tolerance and firepower change to the user through the mode that the rotation rises when user's adjustment gas valve increases output gas volume to further improve the degree of directly perceived of user to the firepower size of cooking utensils.

Preferably, the rotation limiting channel comprises a plurality of inclined channel sections, and the channel height of each inclined channel section changes along with the change of the rotation angle of the valve rod, so that the purpose that the height of the valve rod changes while the valve rod rotates is achieved.

Preferably, the rotation limiting channel further comprises a plurality of horizontal channel sections, the channel height of the horizontal channel sections is unchanged, and the inclined channel sections and the horizontal channel sections are sequentially and alternately arranged.

Above-mentioned structure sets up, through the horizontal channel section that can not change the valve rod height that sets up between the spacing passageway of two adjacent rotations for the user is at the in-process of rotatory valve rod, and the height of valve rod can be the periodic emergence of change, and through this kind of periodic feedback to user's hand, make the user feel cooking utensils firepower more obviously directly perceivedly and rise or descend. Compared with the scheme that the height of the valve rod continuously changes during rotation, the use experience of a user is better.

Preferably, the channel heights of a plurality of the inclined channel sections are different in change amplitude.

Above-mentioned structure sets up, makes the valve rod when the angle of rotation difference, and the slope passageway section all is different to the change of valve rod height to make the user through the change of feeling the valve rod height, can directly know the rotation angle of valve rod.

Preferably, the positioning end moves downward from an initial position and moves into the rotation limiting channel, the valve body further comprises a descending limiting channel, two ends of the descending limiting channel are respectively communicated with the initial position and the rotation limiting channel, and the descending limiting channel accommodates the positioning end when the valve rod moves downward and limits the degree of freedom of movement of the positioning end towards other directions.

Preferably, the valve body further includes an ascending limiting channel, two ends of the ascending limiting channel are respectively communicated with the initial position and the rotation limiting channel, the descending limiting channel receives and limits the positioning end when the valve rod moves upwards, and the channel extending direction of the ascending limiting channel is different from the channel extending direction of the descending limiting channel.

Above-mentioned structure sets up, when making the location end go up and down between initial position and rotatory spacing passageway, rises and descends and can follow different routes and remove, improves the user and uses feeling and experience.

Preferably, the elevation limit passage extends from the initial position to the rotation limit passage obliquely downward in a rotation direction of the valve stem.

Above-mentioned structural arrangement, at the in-process with the initial position of valve rod back-screwing, when the user looses one's hand gradually, the location end of valve rod moves to initial position along rising spacing passageway slant upwards, and can not have like during the ignition clear and definite and step-by-step operation of pushing down the valve rod, rotatory valve rod to operation when making the cooking utensils flame out is more smooth, can obviously improve user experience.

Preferably, the valve body further comprises a one-way limiting structure, the one-way limiting structure is located at a communication position of the ascending limiting channel and the descending limiting channel, and the one-way limiting structure is used for blocking the positioning end from moving into the ascending limiting channel from the descending limiting channel at the initial position, so that the positioning end is effectively prevented from moving downwards to the rotating limiting channel from the ascending limiting channel due to misoperation of a user when the positioning end is at the initial position.

Preferably, a guide structure is arranged on a channel surface of the rotation limiting channel facing to the ascending limiting channel, and the guide structure is used for guiding the moving direction of the positioning end, so that the positioning end can be smoothly moved into the ascending limiting channel from the rotation limiting channel through the guide of the guide structure.

Preferably, the positioning end is a protruding structure protruding horizontally outward from the surface of the valve stem.

Preferably, the valve body comprises an upper limiting surface and a lower limiting surface, and the upper limiting surface and the lower limiting surface are arranged oppositely and form the rotary limiting channel together;

when the valve rod rotates relative to the valve body, the upper limiting surface can limit the displacement of the positioning end in the upward direction, and the lower limiting surface can limit the displacement of the positioning end in the downward direction.

Above-mentioned structure sets up, it is relative at the valve rod when the valve body is rotatory, the displacement of upper limit face can be followed up direction to the location end and restricted, and the displacement of lower limit face can be followed down direction to the location end to no matter when the user is through the mode of pressing and rotatory valve rod, or adjust the firepower size through the mode of lifting and rotatory valve rod, rotatory spacing passageway all can be through the change of self passageway height, makes the change that the user directly perceived firepower size takes place.

Preferably, the upper limit surface and the lower limit surface are both formed on the inner wall surface of the valve body, so that the limit structure of the rotation limit through and the positioning end is hidden inside the valve body.

A hob including a gas valve as described above.

The gas valve of this cooking utensils can make the valve rod take place rotatoryly in modes such as the knob is rotated to the user, when adjusting the firepower size, carry on spacingly and the guide to the location end of valve rod through the rotatory spacing passageway that sets up on the valve body, the rotation angle that makes valve rod and knob changes and corresponds the change according to the valve rod, so that the firepower size of gas can also feed back the user through the altitude variation direct feedback of valve rod, in order to further improve the cognition of user to the firepower size change, when effectively improving the rotatory valve rod of user in order to adjust the firepower, the degree directly perceived to the firepower size cognition of cooking utensils.

A feedback method of stove firepower change is used for feeding back the change of the stove firepower to a user, and comprises the following steps: when the gas knob is rotated to change the firepower of the cooker, the height of the gas knob is increased or decreased according to the change of the firepower of the cooker.

According to the feedback method for the change of the firepower of the cooker, when a user adjusts the firepower in a mode of rotating the knob, the firepower of the cooker is directly fed back to the user in a mode of enabling the height of the gas knob to change along with the firepower, so that the cognition of the user on the change of the firepower is further improved, and the experience of the user in using the cooker is improved.

The positive progress effects of the invention are as follows:

this gas valve, contain its cooking utensils and cooking utensils firepower change's feedback method, make the valve rod take place rotatoryly according to modes such as rotation knob at the user, when adjusting the firepower size, carry on spacingly and the guide to the location end of valve rod through the rotatory spacing passageway that sets up on the valve body, make the high angle that can highly can be according to the valve rod of valve rod change and correspond the change, so that the firepower size of gas can also feed back to the user through the altitude variation of valve rod, further improve the user to the cognition of firepower size change, when effectively improving the rotatory valve rod of user in order to adjust the firepower, the cognitive directly perceived degree of firepower size to cooking utensils, experience with the use that promotes the user feels.

Drawings

Fig. 1 is a schematic structural view of a gas valve according to embodiment 1 of the present invention.

Fig. 2 is an internal structural view (one) of a gas valve according to embodiment 1 of the present invention.

Fig. 3 is a partially enlarged view of a portion a of fig. 2.

Fig. 4 is a schematic structural view of a valve body according to embodiment 1 of the present invention.

Fig. 5 is a schematic structural view of a valve stem of a gas valve according to embodiment 1 of the present invention.

Fig. 6 is a partial structural schematic view of a valve body according to embodiment 1 of the present invention.

Fig. 7 is an expanded view of the layout of the rotation restricting passage of the valve body according to embodiment 1 of the present invention.

Fig. 8 is an expanded view of the layout of the rotation restricting passage of the valve body according to embodiment 2 of the present invention.

Description of reference numerals:

valve body 1

Rotation limiting channel 11

Inclined channel segment 111

Horizontal channel segment 112

Descending limit channel 12

Ascending limit channel 13

One-way limiting structure 14

Elastic member 141, stopper 142

Guide structure 15

Upper limiting surface 16

Lower limiting surface 17

Valve rod 2

Positioning end 21

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.

Example 1

The invention provides a kitchen range which comprises a gas valve and a gas knob. Wherein, as shown in fig. 1, the gas valve includes valve body 1 and valve rod 2, and valve rod 2 can be relative valve body 1 is rotatory, and the top at valve rod 2 is installed to gas knob (not shown in the figure), and the user makes the gas in the gas valve switch on to the combustor of cooking utensils through pressing the gas knob, later, through rotatory gas knob to change the gas volume of gas valve to the furnace end (not shown in the figure) output of cooking utensils.

As shown in fig. 2 to 4, the valve stem 2 of the gas valve has a positioning end 21 for positioning on the inner wall surface of the valve body 1, the positioning end 21 is embodied as a protruding structure formed on the outer surface of the valve stem 2 and protruding horizontally outward (see fig. 5), and a rotation limiting passage 11 (see fig. 4) is correspondingly provided on the inner wall of the valve body 1, the rotation limiting passage 11 being adapted to receive and limit the positioning end 21 when the valve stem 2 is rotated, so that the positioning end 21 can be rotated in a specific direction. As shown in fig. 2, the passage height of the rotation limiting passage 11 is not constant, but varies correspondingly with the variation of the rotation angle of the valve stem 2.

This gas valve can rotate the knob so that valve rod 2 takes place rotatoryly at the user, and when adjusting the firepower size, carry on spacingly and the guide to the location end 21 of valve rod 2 through the rotatory spacing passageway 11 that sets up on valve body 1, the rotation angle that makes valve rod 2 and knob changes and corresponds the change according to valve rod 2, so that the firepower size of gas can also give the user through the altitude variation direct feedback of valve rod 2, further improve the cognition of user to the firepower size change, when effectively improving the rotatory valve rod 2 of user in order to adjust the firepower, the degree of directly perceived to the firepower size of cooking utensils.

Specifically, as shown in fig. 6, the inner wall surface of the valve body 1 has an upper limit surface 16 and a lower limit surface 17, and the upper limit surface 16 and the lower limit surface 17 are disposed to face each other and together form the rotation limit passage 11. When the valve rod 2 rotates relative to the valve body 1, the upper limiting surface 16 can limit the displacement of the positioning end 21 in the upward direction, and the lower limiting surface 17 can limit the displacement of the positioning end 21 in the downward direction, so that when the fire power is adjusted by pressing and rotating the gas knob or lifting and rotating the gas knob by a user, the rotating limiting channel 11 can change the height of the channel, so that the user can intuitively feel the change of the fire power through the height change of the gas knob when rotating the gas knob.

When driving valve rod 2 to rotate through rotatory gas knob, the gas volume that the gas valve exported also can change thereupon, and in this embodiment, the passageway height of rotatory spacing passageway 11 corresponds the change along with the change of the output gas volume of gas valve. For example, after the gas knob is rotated from the zero point, the output gas quantity of the gas valve starts to increase, when the gas knob is rotated to the 90-degree position, the output gas quantity reaches the maximum, and in the process of continuously rotating the gas knob to 180 degrees, the output gas quantity is correspondingly reduced. Therefore, the height of the rotation limiting channel 11 is increased along with the increase of the gas flow and then correspondingly reduced along with the reduction of the gas flow along with the change of the gas flow, so that the rotation limiting channel is correspondingly matched with the intuitive feeling of the firepower of the cooking range adjusted by the rotation of the gas knob by the user, and the intuitive degree of the user for the firepower of the cooking range is further improved.

Specifically, as shown in fig. 7, the rotation limiting channel 11 is composed of a plurality of horizontal channel sections 112 with different heights and arc transition sections between the horizontal channel sections 112, and in the rotation process of the valve rod 2, the positioning end 21 moves from one horizontal channel section 112 to another horizontal channel section 112 with different heights to realize the height change of the valve rod 2, and the height change is step-wise rather than continuously unchanged, so that the height change of the valve rod 2 is more obvious to the feedback of the hand of the user, and the user can intuitively feel the change of the fire power.

After the gas knob is rotated from the zero point, the height of the first horizontal channel section 112 is the lowest, and the height of the subsequent horizontal channel section 112 is gradually increased until the gas knob is rotated to the 90-degree position, the height of the subsequent horizontal channel section 112 is decreased, but when the gas knob is rotated to the 180-degree position, the height of the corresponding horizontal channel section 112 is still higher than the height of the corresponding horizontal channel section 112 when the gas knob is positioned at the zero point.

In this embodiment, the positioning end 21 is moved downward from the initial position (i.e. the position of the positioning end 21 in fig. 3) and moved into the rotation limiting channel 11, i.e. the valve rod 2 is pressed down to perform the ignition operation, and then rotated to perform the operation of changing the fire power of the cooker.

Specifically, as shown in fig. 3 and 4, an ascending limit passage 13 and a descending limit passage 12 are correspondingly provided inside the valve body 1. Wherein, the two ends of the descending limit channel 12 are respectively communicated with the initial position and the rotation limit channel 11, the descending limit channel 12 accommodates the positioning end 21 when the valve rod 2 moves downwards, and limits the freedom degree of the positioning end 21 moving towards other directions except the descending direction. And the spacing passageway 13 that rises then is located the side of the spacing passageway 12 that descends, the both ends of the spacing passageway 13 that rises also communicate initial position and rotatory spacing passageway 11 respectively, the spacing passageway 12 that descends holds and limits location end 21 when valve rod 2 upward movement, can see from the figure, the spacing passageway 12 that descends is vertical downwardly extending, and the spacing passageway 13 that rises then is along the direction of rotation slope extension of valve rod 2 for the rising and the decline of valve rod 2 can be followed two different routes and removed, with the use experience that provides a difference for the user.

In addition, a guide structure 15 is correspondingly arranged on the channel surface of the rotation limiting channel 11 facing the ascending limiting channel 13, and the guide structure 15 provides an arc surface for guiding the moving direction of the positioning end 21, so that the positioning end 21 can be smoothly moved into the ascending limiting channel 13 through the guide of the guide structure 15 under the condition that a user does not press the gas knob and simultaneously rotates back the gas knob.

Since the ascending limit channel 13 extends from the initial position to the rotation limit channel 11 obliquely downward along the rotation direction of the valve rod 2, in the process that the user rotates the gas knob to the initial position, the positioning end 21 of the valve rod 2 moves obliquely upward along the ascending limit channel 13 to the initial position in the process that the user gradually looses his hand, so that in the process that the gas knob is rotated back to the initial position, there will be no definite staged operations such as pressing down the gas knob and rotating the gas knob as in the ignition.

Preferably, as shown in fig. 4, the inner wall surface of the valve body 1 further has a one-way limiting structure 14, the one-way limiting structure 14 is located at a communication position of the ascending limiting channel 13 and the descending limiting channel 12, and the one-way limiting structure 14 is used for blocking the positioning end 21 from moving into the ascending limiting channel 13 from the descending limiting channel 12 at the initial position, so that the positioning end 21 is effectively prevented from moving downwards from the ascending limiting channel 13 to the rotation limiting channel 11 due to misoperation of a user when the positioning end 21 is at the initial position.

Specifically, the one-way position-limiting structure 14 includes a compressible elastic member 141 and a stopper 142, the stopper 142 is connected to the inner wall surface of the valve body 1 through the elastic member 141, and the stopper 142 has an inclined surface toward the upward movement-limiting passage 13 side, so that the positioning end 21 compresses the elastic member 141 through the stopper 142 from the upward movement-limiting passage 13 side, and the passage into the downward movement-limiting passage 12 is opened; the stopper 142 is a plane perpendicular to the moving path of the positioning end 21 on the side of the downward limiting passage 12, so as to block the positioning end 21 when the positioning end 21 is going to enter the upward limiting passage 13 through the one-way limiting structure 14. In this embodiment, the stopper 142 and the elastic member 141 are compressed downward in the vertical direction when the positioning end 21 moves from the ascending limit path 13 into the descending limit path 12.

The invention also provides a feedback method of the fire change of the cooker, which is used for feeding back the fire change degree of the cooker to a user, and the feedback method of the fire change of the cooker comprises the following steps: when a user changes the firepower of the cooker in a mode of rotating the gas knob, the height of the gas knob is increased or decreased corresponding to the firepower change of the cooker, so that the firepower of the cooker is relatively and visually fed back to the user, the cognition of the user on the firepower change is further improved, and the experience of the user in using the cooker is improved.

In order to enable the height of the gas knob to rise or fall corresponding to the change of the firepower of the cooker, a mode of arranging a rotation limiting channel with the changed height in the valve body is provided in the embodiment. Of course, other structures and schemes in the prior art can also achieve the purpose of correspondingly ascending or descending the height of the gas knob.

Example 2

The present embodiment further provides a cooker, which has a structure substantially the same as that of the cooker provided in embodiment 1, except that in this embodiment, as shown in fig. 8, the rotation limiting channel 11 may be divided into a plurality of inclined channel sections 111 and horizontal channel sections 112, and the inclined channel sections 111 and the horizontal channel sections 112 are sequentially and alternately arranged. The channel height of each inclined channel section 111 changes along with the change of the rotation angle of the valve rod, namely, when the positioning end 21 moves in the inclined channel section 111, the height of the positioning end, which is limited by the inclined channel section 111 and changes along with the rotation of the valve rod, changes correspondingly, so that the purpose that the height of the valve rod changes while the valve rod rotates is achieved.

And the horizontal channel segments 112 are spaced between two adjacent rotation limiting channels 11. For a single horizontal channel segment 112, the channel height is constant, i.e., the positioning end 21 is limited by the horizontal channel segment 112 as it moves within the horizontal channel segment 112, but the height does not change with the rotation of the valve stem. A different solution is provided by providing a horizontal channel section 112 between the two rotation limiting channels 11 to continuously change the embodiment of the valve stem as it rotates relative to the rotation limiting channels 11. In the scheme, the horizontal channel section 112 which does not change the height of the valve rod is arranged between the two adjacent rotary limiting channels 11, so that the height of the valve rod (namely a gas knob) can be changed in a staged manner in the process of rotating the valve rod by a user, and the user can feel that the firepower of the stove is rising or falling more obviously and intuitively through the staged feedback to the hand of the user. This graduated feedback may be relatively better perceived by the user as the user experiences than the height of the valve stem (also equivalent to a gas knob) continuously changes as it is rotated.

As can be seen from fig. 8, the channel height variation amplitude of each inclined channel segment 111 in the present embodiment is the same. Of course, in other embodiments, the channel height variation amplitude of each inclined channel segment 111 may also be different. Specifically, after the gas knob is rotated from the zero point, the slope of the first inclined channel segment 111 is relatively low, and then the slope of each inclined channel segment 111 rises. When the gas knob is rotated to the 90 ° position, the positioning end 21 is located in one of the horizontal channel sections 112, the valve rod is rotated and the positioning end 21 is moved into the inclined channel sections 111 which are inclined downward, and thereafter, the slope of each inclined channel section 111 is lowered until the gas knob is rotated to the 180 ° position.

Make the valve rod when the angle of rotation difference through above-mentioned setting, slope passageway section 111 all is different to the change of valve rod height to make the user through the change of feeling the valve rod height, can directly know the rotation angle of valve rod. Further, the inclined channel section 111 has a larger change range of the height of the valve rod when the firepower of the cooker is large, so that a user can intuitively know that the firepower of the cooker is in a big fire state through a great height change when the gas knob is rotated.

In addition, between each horizontal channel segment 112 and the inclined channel segment 111, an arc transition may be provided to avoid the positioning end 21 from being caught between the horizontal channel segment 112 and the inclined channel segment 111.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.

Claims

1. A gas valve, it includes valve body and valve rod, the valve rod can be relative the valve body is rotatory, the valve rod has the location end of location in the valve body, its characterized in that, the valve body includes rotatory spacing passageway, rotatory spacing passageway is in the valve rod is rotatory the time holds and spacing location end, the passageway height of rotatory spacing passageway is along with the rotation angle of valve rod changes and changes.

2. A gas valve as claimed in claim 1, wherein the gas valve varies the output gas amount of the gas valve based on the rotation angle of the valve stem, and the passage height of the rotation-restricting passage varies with the output gas amount of the gas valve.

3. A gas valve as claimed in claim 2, wherein the channel height of the rotation-limiting channel increases with increasing output gas of the gas valve.

4. A gas valve as claimed in claim 1, wherein the rotation-limiting passage comprises a plurality of inclined passage sections, each of which has a passage height that varies with the angle of rotation of the valve stem.

5. A gas valve as claimed in claim 4, wherein the rotation-limiting passage further comprises a plurality of horizontal passage sections, the passage height of the horizontal passage sections is constant, and the inclined passage sections and the horizontal passage sections are alternately arranged in sequence.

6. A gas valve as claimed in claim 4, wherein the channel heights of the inclined channel segments all vary by different magnitudes.

7. A gas valve as claimed in claim 1, wherein the positioning end moves downward from an initial position and into the rotation-limiting passage, and the valve body further comprises a descent-limiting passage having both ends communicating with the initial position and the rotation-limiting passage, respectively, the descent-limiting passage accommodating the positioning end when the valve stem moves downward and limiting the degree of freedom of movement of the positioning end in other directions.

8. A gas valve as claimed in claim 7, wherein the valve body further comprises an ascending limit passage having both ends respectively communicating the initial position and the rotation limit passage, and the descending limit passage receives and limits the positioning end when the valve stem moves upward, the ascending limit passage having a passage extending direction different from that of the descending limit passage.

9. A gas valve as claimed in claim 8, wherein the rise-limiting passage extends obliquely downward from the initial position to the rotation-limiting passage in the direction of rotation of the valve stem.

10. A gas valve as claimed in claim 9, wherein the valve body further comprises a one-way stop located at a communication of the rise-stop passage and the fall-stop passage, the one-way stop being for blocking movement of the locating end from the fall-stop passage into the rise-stop passage at the initial position.

11. A gas valve as claimed in claim 8, wherein the surface of the rotation-limiting passage on the side facing the ascent-limiting passage is provided with a guide structure for guiding the direction of movement of the positioning end.

12. A gas valve as claimed in claim 1, wherein the locating end is a projecting formation projecting horizontally outwardly from the surface of the valve stem.

13. A gas valve as claimed in claim 1, wherein the valve body comprises an upper and a lower limiting surface, the upper and lower limiting surfaces being disposed in opposition and together forming the rotational limiting passage;

14. A gas valve as claimed in claim 13, wherein the upper and lower retainer surfaces are formed on an inner wall surface of the valve body.

15. A hob, characterized in that it comprises a gas valve according to any one of the claims 1 to 14.

16. A feedback method for stove firepower change is characterized by being used for feeding back the change of the stove firepower to a user, and the feedback method for the stove firepower change comprises the following steps: when the gas knob is rotated to change the firepower of the cooker, the height of the gas knob is increased or decreased according to the change of the firepower of the cooker.