CN210669844U

CN210669844U - Power generation device for battery-free tire pressure monitoring transmitter

Info

Publication number: CN210669844U
Application number: CN201921446555.3U
Authority: CN
Inventors: 向英特
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-09-02
Filing date: 2019-09-02
Publication date: 2020-06-02
Anticipated expiration: 2029-09-02

Abstract

The utility model discloses a power generation device for a battery-free tire pressure monitoring transmitter, which comprises a solenoid 1, a permanent magnet 2, a hollow cylinder 3, a magnetic conduction cover 4, a magnetic conduction ring 5, a sliding column 6 and a spring 7, wherein the upper end surface and the lower end surface of the permanent magnet 2 are respectively pasted with the magnetic conduction cover 4, and the permanent magnet and the sliding column 6 are penetrated through a central through hole to do piston movement together; the solenoid 1 is arranged in a concave ring groove formed by symmetrically buckling two magnetic conduction rings 5 together, the magnetic conduction rings 5 are fixed on the inner wall of the middle section of the hollow cylinder 3, two annular magnetic gaps are formed between the magnetic conduction rings 5 and the magnetic conduction cover 4, and when the permanent magnet 2 and the magnetic conduction cover 4 do piston motion together, the magnetic surfaces forming the magnetic gaps and the distance between the magnetic surfaces are changed, so that the magnetic flux of the coil in the solenoid 1 is rapidly changed to generate electricity; the utility model has the advantages of high generating efficiency and small volume, and is suitable for the development and production of the tire pressure monitor without the battery; the generator is installed taking into account the center of gravity of the transmitter.

Description

Power generation device for battery-free tire pressure monitoring transmitter

Technical Field

The utility model belongs to the auto-parts field discloses a power generation facility for having battery tire pressure monitoring transmitter, is applicable to the development and the production of having battery tire pressure monitoring appearance.

Background

The tire pressure monitoring instrument in the current market basically adopts the lithium battery for power supply, the lithium battery has the requirement of high temperature resistance, the manufacturing cost is higher, the battery needs to be replaced in a certain time, the replacement cost is not too high, although along with the development of the battery technology, the energy density of the lithium battery is higher and higher, the battery does not need to be replaced in all the years, but the tire pressure monitoring instrument powered by self-power generation does not have the market, on the contrary, as long as the self-power generation technology is mature, the cost is reduced, and the battery-free tire pressure monitoring transmitter which does not need to be internally provided with the battery and does not need to be replaced always can obtain a place and become a product line. Here, the battery-free means that the tire pressure monitor product is required to comprise a power generation device, the kinetic energy generated by the rotation of the tire is utilized to generate electricity, and the power supply problem of the pressure detection chip and the wireless data transmission chip in the tire pressure monitor is solved after the treatment such as the rear-stage rectification, the electricity storage and the like.

As is well known, electromagnetic induction is one of the most basic physical phenomena, which is the basic principle technology of many large generators on the market, and in such a subdivided field as tire pressure monitoring instruments, the use of electromagnetic induction for power generation has higher practicability than other methods like piezoelectric conversion, acoustic energy conversion, electromagnetic coupling, etc., and at least, it should play an important role in the first generation of battery-less tire pressure monitoring and power generation instruments. The electromagnetic power generation is classical, and the key point is how to have a better structure, the most typical structure of the current electromagnetic power generation is that a permanent magnet simply makes a piston motion in a coil to enable the coil to cut magnetic lines of force to generate power, and the energy source of the piston motion is the rolling of wheels on a bumpy road surface. The arrangement of the permanent magnet directly in the coil for piston motion power generation is the most conceivable structure scheme, but the scheme has poor practicability and is caused by an inherent defect: if radial magnetization is adopted, two offset voltages with opposite directions exist in induced voltage in the coil, the power generation efficiency is not high, so the permanent magnet is only supposed to be axially magnetized, when the axially magnetized permanent magnet reciprocates in the coil, the whole magnetic force line is in a linear motion state, because the dense magnetic force line is positioned on two end faces, a loop from an N pole to an S pole is relatively dispersed in space, the magnetic force line at the dense position is not directly intersected with the coil, the permanent magnet must do large-amplitude motion in the coil, and the direct result is that the permanent magnet needs a larger piston motion distance, the size of the power generation device is increased invisibly, and the practicability of the structure is hindered.

Therefore, the inventor of the present invention considers that the permanent magnet power generation structure of the coil built-in piston motion needs to be improved, the best mode is to use the magnetic conductive material to guide and restrain the magnetic field, so that the magnetic flux changes faster, and according to the faraday's law of electromagnetic induction, we know that the magnitude of the induced electromotive force is in direct proportion to the speed of the magnetic flux change, which is important for the self-generating device, and the difficulty of the post-processing can be reduced as long as the peak value of the induced voltage is increased; and the piston stroke can be reduced by magnetic field guiding, because the magnetic field guiding can change the loop of magnetic lines of force emitted by the permanent magnet in space, the distribution of the magnetic lines of force in space is further changed, and after the magnetic lines of force are elaborately designed, the piston does not need too long path in motion, and the same power generation effect as the coil piston type structure can be achieved.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects of a power generation structure that a permanent magnet does piston motion in a coil, a permanent magnet and a coil are respectively coated by a magnetic conduction cover and a magnetic conduction ring with low magnetic resistance, so that magnetic lines of force emitted by the permanent magnet are conducted and restrained, the return flow path of the magnetic lines of force is switched by utilizing the position relation of the piston motion, the purpose of more high efficiency of the magnetic flux change rate of the coil in the coil is realized, and the effects of high power generation efficiency and small volume are achieved.

In order to achieve the purpose, the following technical scheme is used:

a power generation device for a battery-free tire pressure monitoring transmitter comprises a coil, a permanent magnet and a spring, wherein the coil, the permanent magnet and the spring are fixed in a spherical battery-free tire pressure monitoring transmitter and provide working electric energy for the spherical battery-free tire pressure monitoring transmitter; when the hollow cylinder is observed in a vertical posture, the hollow cylinder is provided with a cylindrical cavity, two ends of the hollow cylinder are closed, the center of the closed end surface is provided with a small hole, and a sliding column made of a non-magnetic material is fixed in the hole; the permanent magnet is cylindrical, the magnetizing direction is axial magnetizing, the upper end surface and the lower end surface are respectively and symmetrically adsorbed by a magnetic conduction cover, the axial centers of the permanent magnet and the magnetic conduction cover are provided with through holes, and the permanent magnet and the magnetic conduction cover can freely slide up and down together after penetrating through the sliding column; the magnetic conduction cover is a cylindrical sheet, the diameter of the magnetic conduction cover is slightly larger than that of the permanent magnet, and a circular concave platform for adsorbing the permanent magnet is arranged on one end face of the magnetic conduction cover; the coil is a multi-turn coil wound by an enameled wire and is embedded into a concave ring groove formed by symmetrically buckling two magnetic conductive rings together, and the two magnetic conductive rings are further fixed on the inner wall of the middle section of the hollow cylinder; the center of the magnetic conduction ring is provided with a hole with the diameter larger than that of the magnetic conduction cover, so that the magnetic conduction cover and the permanent magnet do piston motion in the hole in the up-down direction; two annular magnetic gaps for passing through magnetic lines of force are formed between the inner wall of the opening of the magnetic conduction ring and the outer wall of the magnetic conduction cover, when the permanent magnet and the magnetic conduction cover move together to form a piston, the distances between the magnetic faces forming the magnetic gaps and between the magnetic faces are changed, the magnetic flux of the multi-turn coil in the coil is further changed to generate electricity, the magnetic gaps play a role in selecting a magnetic circuit and changing the magnetic resistance, and therefore the effects of shortening the movement stroke of the permanent magnet and increasing the change rate of the magnetic flux in the coil are achieved, and the device is easy to obtain high induction voltage.

The magnetic gap interval is short, the magnetic conduction cover and the magnetic conduction ring which form the magnetic gap are made of soft magnetic materials, so that strong magnetic field attraction force exists in the annular magnetic gap, the annular magnetic attraction force is mutually offset in the radial direction, but the permanent magnet and the magnetic conduction cover are attracted by the magnetic attraction force to be in a suspended state which is easy to elastically vibrate up and down as a piston, the suspended state is further changed into a piston motion state when the magnetic gap is subjected to top vibration, and the elastic vibration is favorable for absorbing top vibration energy existing in the tire; the two springs are respectively supported on the two magnetic conductive covers and used for rebounding the permanent magnet and the magnetic conductive covers to the middle section of the hollow cylinder, so that the permanent magnet and the magnetic conductive covers always return to the suspended state after the piston moves.

Furthermore, a toroidal transformer for boosting is also installed in the idle space, the induced voltage output by the coil is boosted to improve the induced output voltage, and the idle space is an unused annular space close to the upper end and the lower end in the hollow cylinder; the annular transformer is placed in the space, so that the internal space of the hollow cylinder can be fully utilized, and mechanical motion interference with the permanent magnet and the piston motion of the magnetic conduction cover can not be formed.

The utility model discloses the beneficial effect who brings is: the magnetic gap between the magnetic conduction cover and the magnetic conduction ring has the double functions of magnetic circuit selection and magnetic resistance change, the stroke of the permanent magnet for piston movement is greatly shortened, and the time required by the piston movement is reduced while the stroke is shortened, so that the magnetic flux change rate is improved, and the voltage for induction power generation is increased; in addition, the magnetic field is restrained by the magnetic conduction cover and the magnetic conduction ring, the magnetic leakage is small, the absolute value of the change of the magnetic flux is also improved, and the magnetic flux is beneficial to improving the power generation voltage; obviously, the utility model discloses there are two practicality's advantage: the motion path of the piston is reduced, which is beneficial to the small size of the device; the magnetic leakage is reduced, the magnetic flux change rate is improved, and the generation efficiency is improved, so that higher generation voltage is obtained.

Drawings

The drawings herein include examples for illustrating aspects of the present invention and methods of operation, and are not intended to represent a limitation on the invention, but rather are intended to illustrate principles and aspects of the present invention and, together with the description, serve to explain the principles and aspects of the present invention.

Fig. 1 is a schematic structural diagram of embodiment 1.

Fig. 2 is an exploded view of the structure of example 1.

Fig. 3 shows the trend of the magnetic line loop when the permanent magnet and the magnetic conductive cover are still, and the magnetic flux in the coil is maximum at the moment.

Fig. 4 shows the magnetic line of force after the permanent magnet and the magnetic conductive cover move upward together for a stroke, which illustrates that the change of the magnetic gap causes the switching of the magnetic line of force loop, and the magnetic flux in the coil is very small at this time.

Fig. 5 is a schematic structural diagram of embodiment 2, which is different from embodiment 1 in that a toroidal transformer for boosting is installed in an idle space inside a hollow cylinder, so as to facilitate processing such as rectification, voltage conversion, electric energy storage and the like at a later stage.

Fig. 6 is an exploded view of the structure of example 2.

Fig. 7 shows a typical application example of the embodiment of the present invention in a battery-less tire pressure monitoring transmitter.

In the figure:

1-coil, 2-permanent magnet, 3-hollow cylinder, 3A-sealing cover, 4-magnetic conductive cover, 5-magnetic conductive ring, 6-sliding column, 7-spring, 8-ring transformer;

41-42-magnetic surfaces forming magnetic gaps on the magnetic conducting covers, and 51-53-magnetic surfaces forming magnetic gaps on the magnetic conducting rings;

10-the embodiment of the utility model, 20-balancing weight, 30-open porose and have elastic hollow spheroid, 40-other circuit part of tire pressure monitor, 50-no battery tire pressure monitor, 60-tire.

Detailed Description

The technical solution of the invention is explained in detail and as far as possible in the following embodiments with reference to the accompanying drawings.

Example 1

FIG. 1 is a schematic structural diagram of an embodiment. The coil (1) is a multi-turn coil wound by an enameled wire, the number of turns is more, two magnetic conduction rings (5) with round holes in the centers are symmetrically buckled together to form a groove, and the coil (1) is just placed in the groove, so that except for the ring surface at the inner ring of the coil (1), other surfaces are covered by magnetic conduction substances, namely, the other surfaces have low reluctance paths, and the magnetic force lines passing through the outer side of the coil (1) can return in low reluctance path runoff; the permanent magnet (2) is cylindrical, the magnetizing direction is axial magnetizing, namely the magnetizing in the motion direction of the piston, and the upper end and the lower end of the permanent magnet are both stuck with magnetic conduction covers (4); the magnetic conduction cover (4) is a cylindrical sheet, one end face of the magnetic conduction cover is provided with a concave platform matched with the permanent magnet (2), and the diameter of the concave platform is matched with that of the permanent magnet (2), so that the permanent magnet (2) can be embedded into a point, and thus, the upper magnetic pole and the lower magnetic pole of the permanent magnet (2) are covered by the magnetic conduction cover (4), so that the vertical magnetic force lines of the two magnetic poles of the permanent magnet (2) can change directions to be horizontal; the permanent magnet (2) and the magnetic conduction cover (4) are provided with holes at the shaft centers, so that the permanent magnet and the magnetic conduction cover can penetrate through the vertical sliding column (6) together to do piston motion along the up-down direction; the permanent magnet (2) and the two magnetic conduction covers (4) are tightly combined through magnetic force, and additional adhesive is not needed for auxiliary fixation; the outer diameter of the magnetic conduction cover (4) is smaller than the inner diameter of the round hole of the magnetic conduction ring (5), a magnetic gap with short distance for magnetic lines of force to pass is formed between the cylindrical outer wall of the magnetic conduction cover (4) and the inner wall of the round hole of the magnetic conduction ring (5), the magnetic gap is annular, and the N pole and the S pole of the permanent magnet (2) are respectively arranged; for convenience of description, a fixed magnetic conduction ring (5) and a coil (1) are called as fixed components, a permanent magnet (2) and a magnetic conduction cover (4) which do piston movement are called as movable components, the mechanical connection relationship between the fixed magnetic conduction ring and the movable components is a sliding column (6), and the magnetic field connection relationship is a magnetic gap; when the movable component does piston motion in the fixed component, the magnetic gap is equivalent to a multi-way selection switch in a magnetic circuit, the magnetic resistance of the magnetic gap can be changed due to distance change, and due to the magnetic circuit selection function of the magnetic gap and the magnetic field constraint function of the magnetic conduction cover (4) and the magnetic conduction ring (5), the magnetic flux passing through the coil (1) is changed violently, so that the coil in the coil (1) generates electricity due to electromagnetic induction. Generally, the fixed and movable assemblies are substantially uniform in height; in order to obtain a greater magnetic force, the height of the permanent magnet (2) may be slightly higher, as shown in fig. 1; the hollow cylinder (3) plays a role in fixing the magnetic conduction ring (5) and the sliding column (6), provides accommodating space for other included components, and simultaneously limits the moving space, namely the stroke, of the permanent magnet (2) and the magnetic conduction cover (4).

Because the magnetic gap is smaller, consequently there is magnetism to inhale power between movable assembly and the fixed subassembly, this kind of power is 360 directions around traveller (6), there is horizontal magnetism pulling force to movable assembly, it is offset to make horizontal power generally, make simultaneously movable assembly can be in unsettled state in hollow cylinder (3) middle section, when slightly moving from top to bottom, annular magnetism pulling force can pull back movable assembly to unsettled state, therefore movable assembly who is in this kind of unsettled state easily does the vibration of piston motion nature from top to bottom when receiving the top vibration, be favorable to absorbing the top vibration energy that exists in the tire and generate electricity. The movable assembly continuously performs piston movement on the spool (6) in the stationary assembly while continuously absorbing the tire pitch vibration energy as the embodiment rotates with the host within the tire.

The spring (7) can be a straight spring, preferably a pagoda spring, the main function of the spring (7) is to push the movable assembly formed by the permanent magnet (2) and the magnetic conduction cover (4) back to the middle position in the up-down direction, namely the middle section of the hollow cylinder (3), and the spring in the schemes is mainly used for facilitating the piston movement of the permanent magnet, unlike other schemes. When the magnetic attraction device is static, the magnetic gap is two ring surfaces, so that the magnetic attraction force also comprises two rings which are coaxial up and down; when the permanent magnet (2) and the magnetic conduction cover (4) do piston movement to the upper limit position or the lower limit position, only one ring surface magnetic attraction force is left, even if the magnetic attraction force is applied, the movable assembly can stay at the position, and therefore a spring (7) is needed to bounce the movable assembly back to a suspension state.

The enameled wire for winding the coil (1) can be a common enameled wire, and can also be a thermal bonding enameled wire and an alcohol bonding enameled wire, the wire diameter is 0.02-0.1 mm, the number of turns is not less than 1500 turns, and the thermal bonding enameled wire with the wire diameter of 0.05mm and the alcohol bonding enameled wire are recommended to be used for winding the coil (1) into a 3000-turn hollow coil.

The sliding column (6) is made of copper material without magnetic conductivity, or titanium material which is non-magnetic material can be selected, the surface is required to be very smooth so as to be beneficial to the permanent magnet (2) sleeved on the sliding column and the magnetic conductive cover (4) to do piston movement, the inner hole of the permanent magnet (2) is slightly larger than the inner hole of the magnetic conductive cover (4) so as to avoid the sliding column (6) from directly rubbing with the permanent magnet (2), and lubricating grease can be adopted to further reduce the friction.

The utility model discloses still have an advantage of not being dazzling, be exactly that solenoid (1) is in hollow cylinder (3), and hollow cylinder (3) also play the effect of protective housing, and this is that many other schemes do not possess.

The utility model discloses there is certain requirement in the manufacturing, because machining error, the strength of just inhaling the magnetism between the magnetic gap can not offset in 360 radial faces comprehensively to form a horizontal direction's resultant force, there is frictional resistance when making permanent magnet (2) and magnetic conduction lid (4) slide about traveller (6), hinders permanent magnet (2) and magnetic conduction lid (4) and does the piston motion. Therefore, the machining precision, especially the precision of the magnetic conduction cover (4) and the magnetic conduction ring (5), is controlled as much as possible, which leads to the increase of the cost, and the utility model has the disadvantages of the utility model.

The technical principle behind the magnetic conducting cover (4) and the magnetic conducting ring (5) and how the magnetic gap formed by them controls the magnetic line loop and accelerates the magnetic flux change of the coil in the coil (1) are briefly explained by using fig. 3-4.

Fig. 3 shows the magnetic line loop when the present embodiment is at rest, the magnetic line passes through the magnetic gap formed by 41 and 51 and the magnetic gap formed by 42 and 52, because the magnetic conductive cover (4) and the magnetic conductive ring (5) provide very low magnetic resistance, the direction of most of the magnetic line is shown by the dotted line in the figure, it can be seen that, at present, the magnetic line passes through the coil from bottom to top unidirectionally, so that the magnetic flux in the coil reaches the maximum, because the magnetic gaps (41-51) and the magnetic gaps (42-52) have magnetic attraction, the permanent magnet (2) can be attracted and suspended. The magnetic flux loop on the right half of fig. 3 is completely symmetrical to the left, and is omitted here and is not illustrated.

Fig. 4 shows the magnetic line loop of the permanent magnet (2) of this embodiment, when the piston moves, it is noticed that the original magnetic gap (41-51) is broken, and instead the magnetic gap (42-51) is replaced, and a new magnetic gap (41-53) is established, it can be seen that, during the piston movement, the distance between the two magnetic face pairs forming the magnetic gap and the magnetic face pair is changed, which makes the magnetic line loop selectively and significantly changed like a switch, as shown in fig. 4, the magnetic line enters the coil and then exits the coil, the magnetic flux in the coil is cancelled, as if the magnetic line is short-circuited, it can be seen that the magnetic loop is changed due to the continuous change of the magnetic gap, resulting in a large change of the magnetic flux, and the large change of the magnetic flux occurs in the case of short moving distance of the piston, comparing the positions in fig. 3 and 4, it can be seen that the permanent magnet (2) has not yet been completely moved out of the coil (1) by one position, and the magnetic flux has gone from a maximum to an almost negligible amount. In fig. 4, the original magnetic gaps (42-52) have a larger distance, and the shunted magnetic lines of force change due to the reluctance change, and because the shunts are smaller and ignored by our above analysis, we can only say that the magnetic flux in the coil is very low but not absolutely zero. Similarly, the right magnetic line loop in fig. 4 is completely symmetrical to the left, and is omitted and not illustrated.

The magnetic gap is a magnetic path between the magnetic conduction cover (4) and the magnetic conduction ring (5), and the characteristics of the magnetic gap are dynamically changed due to the change of the relative position between the magnetic conduction cover (4) and the magnetic conduction ring (5), the change is not only reflected in the change of two magnetic surfaces forming the magnetic gap, but also reflected in the change of the distance between the two magnetic surfaces, and the two magnetic surfaces are called as magnetic surface pairs; a magnetic gap can be understood as a magnetic circuit switch with a variation in reluctance, which causes an order of magnitude change in the number of lines of force passing through the coil in the coil (1), and a variation in the quality of the number of lines of force passing through the coil in the coil (1), which causes a rapid change in the magnetic flux without a large stroke. Will from the broad sense, the utility model discloses utilize magnetic conduction material to send magnetic line of force to permanent magnet (2) and lead and restrain in order to optimize the change of coil magnetic flux in solenoid (1), so-called direction is the trend that utilizes the physical shape of magnetic conduction lid (4) and magnetic conduction ring (5) to guide the magnetic line of force and tends to the magnetic gap, so-called restraint is just retraining the magnetic line of force and walking in magnetic conduction material inside, and direction and restraint complement each other, and both have controlled the size of magnetic flux in the coil together. The magnetically permeable material described herein is a so-called soft magnetic material.

Through the comparison of fig. 3~4, the magnetic force line is after direction and restraint, obviously than not having under the condition of magnetic conduction lid (4) and magnetic conduction ring (5), has greatly shortened piston route stroke, simultaneously because the magnetic leakage diminishes, the change absolute value of magnetic flux is also big, another beneficial result that the stroke reduces is that the time of piston motion has also reduced, and relative terrestrial magnetism flux transformation rate has been high, and the generating voltage peak value has just also improved, consequently obtains two advantages of the utility model: the motion path of the piston is reduced, which is beneficial to the miniaturization of the device; the magnetic leakage is reduced, the magnetic flux change rate is improved, and the increase of the generating voltage is facilitated.

The above paragraph mentions the reduction of leakage flux, which is explained briefly here: under the condition that the magnetic conduction cover (4) and the magnetic conduction ring (5) are not arranged, part of magnetic lines at the edge directly return to the S pole from the N pole in the coil, and the permanent magnet is internally arranged from the S pole to the N pole, so that the part of magnetic lines are offset in the coil in one step, the power generation effect is completely avoided, the part of magnetic lines without magnetic field restriction of the permanent magnet (2) is called as leakage flux, and the leakage flux can be considered as a loss of magnetic line divergence. Under the condition of the magnetic conduction cover (4) and the magnetic conduction ring (5), magnetic lines of force basically go away from the magnetic gap and are concentrated inside the magnetic conduction cover (4) and the magnetic conduction ring (5), and the magnetic leakage is greatly reduced.

Note that in fig. 3 to 4, in order to make the drawings look clear, the paths of the magnetic lines are highlighted, and the hatched line segments of the cross sections are not drawn; in addition, the path of the magnetic force line is simplified and regulated; in addition, sometimes, the coil is expressed as a coil, and the two meanings are almost equal; the small circles arranged in a matrix in fig. 3-4 are the cross sections of enameled wires in a coil.

Example 2

The difference between the embodiment and the embodiment 1 is that the empty space inside the hollow cylinder (3) is utilized, namely, the unused annular space near the upper end and the lower end inside the hollow cylinder (3). An annular transformer (8) for boosting is arranged in the idle space, referring to fig. 5, the annular transformer (8) is arranged below the hollow cylinder (3) and does not hinder the permanent magnet (2) and the magnetic conduction cover (4) from doing piston motion together; the output of the coil (1) is directly connected with the input of the toroidal transformer (8), and the output of the toroidal transformer (8) is used as the power generation output of the device. The toroidal transformer (8) is added, so that rectification, voltage conversion and electric energy storage can be performed on a rear stage, and generally, the voltage boosting ratio of the toroidal transformer is 3-5 times. For clarity of presentation, the parts of FIGS. 5-6 that are identical to those of embodiment 1 are not identified by a numerical designation.

Fig. 7 shows a typical application example of the present invention in a batteryless tire pressure monitoring transmitter, wherein the batteryless tire pressure monitoring transmitter (50) is freely placed in a tire (60), a hollow sphere (30) with a hole and elasticity is used as a shell, and a balancing weight (20) indicated by a dotted frame controls the center of gravity of the hollow sphere so that the center of gravity is not at the center of the sphere but is deviated to one side of the center of the sphere; the utility model discloses an installation of embodiment (10) must guarantee that the focus of emission appearance (50) is located the utility model discloses arbitrary embodiment (10) is on the axis of hollow pipe (3), so, after tire (60) played with medium-high speed rotation, under the effect of centrifugal force, the spheroid (30) of no battery tire pressure monitoring emission appearance (50) was close to the inner wall contact of focus one side and tire (60), and hug closely on the inner wall of tire (60) and rock and sway and have along with top-bottom jolt vibration with this as the fulcrum, this kind of jolt vibration is very obvious when the tread contacts to the ground; in the driving process of the automobile, the line connecting the gravity center of the launcher (50) and the sphere center and the axis of the hollow tube (3) basically keep the collinear relation, thus the utility model can work well. The size of embodiment (10) of the present invention is roughly as shown in fig. 7 in the sphere, and the other places left are used for laying out other circuit parts (40) of the tire pressure monitor, as shown by the dotted frame in fig. 7.

As for the material of balancing weight (20) can be the proportion is bigger and not magnetic conduction raw materials, also can be that certain spare part of tire pressure monitoring generator constitutes as long as enable whole spheroidal focus and keep away from the centre of sphere, for example work as the utility model discloses an embodiment is heavier and under the relatively lighter condition of other parts, the weight of embodiment itself has just played the effect of control focus, no longer needs other balancing weights, the centrobaric scheme of control, the utility model discloses needn't also can not make here and prescribe a limit.

It should be noted that the above description of a typical application of the present invention is only intended for the purpose of further explanation of the present invention, i.e. to help the reader to deepen the understanding of the technical solution through the application scenario example, and should not be construed as an undue limitation on the application of the present invention.

Claims

1. A power generation device for a battery-less tire pressure monitoring transmitter, characterized in that: the device comprises a solenoid (1), a permanent magnet (2) and a spring (7), wherein the solenoid (1), the permanent magnet (2) and the spring (7) are fixed in a spherical battery-free tire pressure monitoring transmitter and provide working electric energy for the spherical battery-free tire pressure monitoring transmitter, and the gravity center of the transmitter is far away from the spherical center and is positioned on the axis of the solenoid (1); the power generation device also comprises a hollow cylinder (3), a magnetic conduction cover (4), a magnetic conduction ring (5) and a sliding column (6), and all the parts are coaxial; when the hollow cylinder (3) is observed in a vertical posture, the hollow cylinder (3) is provided with a cylindrical cavity, two ends of the hollow cylinder are closed, the center of the closed end surface is provided with a small hole, and a sliding column (6) made of a non-magnetic material is fixed in the hole; the permanent magnet (2) is cylindrical, the magnetizing direction is axial magnetizing, the upper end surface and the lower end surface are respectively and symmetrically adsorbed by one magnetic conduction cover (4), the axial centers of the permanent magnet (2) and the magnetic conduction cover (4) are provided with through holes, and the permanent magnet (2) and the magnetic conduction cover (4) are penetrated on the sliding column (6) together and can freely slide up and down; the magnetic conduction cover (4) is a cylindrical sheet, the diameter of the magnetic conduction cover is slightly larger than that of the permanent magnet (2), and a circular concave platform for adsorbing the permanent magnet (2) is arranged on one end face of the magnetic conduction cover; the coil (1) is a multi-turn coil wound by an enameled wire and is embedded into a concave ring groove formed by symmetrically buckling two magnetic conduction rings (5), and the two magnetic conduction rings (5) are further fixed on the inner wall of the middle section of the hollow cylinder (3); a hole with the diameter larger than that of the magnetic conduction cover (4) is arranged in the center of the magnetic conduction ring (5) and is used for the magnetic conduction cover (4) and the permanent magnet (2) to do piston motion in the hole along the up-down direction; two annular magnetic gaps for passing through magnetic lines of force are formed between the inner wall of the opening of the magnetic conduction ring (5) and the outer wall of the magnetic conduction cover (4), when the permanent magnet (2) and the magnetic conduction cover (4) do piston motion together, the distance between the magnetic faces forming the magnetic gaps and the distance between the magnetic faces are changed, and the magnetic flux of a plurality of turns of coils in the coil (1) is further changed to generate electricity; due to the magnetic field attraction existing in the magnetic gap, the permanent magnet (2) and the magnetic conduction cover (4) are attracted by the magnetic attraction force to be in a suspended state which is easy to elastically vibrate up and down as a piston, and the suspended state is further changed into a piston motion state when the piston is subjected to jolt vibration; the two springs (7) are respectively propped against the two magnetic conduction covers (4) and are used for rebounding the permanent magnet (2) and the magnetic conduction covers (4) to the middle section of the hollow cylinder (3).

2. The power generation device for a batteryless tire pressure monitoring transmitter of claim 1, wherein: and an annular transformer for boosting is also arranged in the idle space, and the idle space is an unused annular space close to the upper end and the lower end in the hollow cylinder (3).