CN201215036Y

CN201215036Y - Pneumatic thermostat

Info

Publication number: CN201215036Y
Application number: CNU2008200673995U
Authority: CN
Inventors: 邱新桥; 王荣志
Original assignee: Hubei University of Automotive Technology
Current assignee: Hubei University of Automotive Technology
Priority date: 2008-05-20
Filing date: 2008-05-20
Publication date: 2009-04-01
Anticipated expiration: 2018-05-20

Abstract

The utility model provides a pneumatic-type thermostat with cheap temperature sensitive medium, simple structure, stable property and long service life, which is composed of a valve driving mechanism, a valve mechanism and a bracket; the valve driving mechanism is arranged below the valve mechanism, and the valve driving mechanism is composed of a temperature-sensing cylinder, an expansion membrane, a piston stroke limit retainer ring, a piston, a piston rod and a cylinder; the piston is matched with the inner cavity of the cylinder, the piston rod is connected with the piston, the head part of the piston rod penetrates out of the upper end of the cylinder to be butted on the valve of the valve mechanism, the piston stroke limit retainer ring is arranged at the lower end of the cylinder, and the upper end of the cylinder and the piston are provided with vent holes; the inner cavity of the temperature-sensing cylinder is filled with liquid with the boiling point of 50 DEC C to 70 DEC C, the expansion membrane is arranged at the opening of the temperature-sensing cylinder, and the periphery of the expansion membrane and the temperature-sensing cylinder are gas-sealed; and the temperature-sensing cylinder is arranged at the lower end of the cylinder and connected with the cylinder to be as a whole which is connected with the bracket. The utility model is characterized by the switch of the valve which is controlled through air pressure generated by liquid evaporization.

Description

A kind of pneumatic type thermostat

Technical field

The utility model is a kind of device of control circle fluid flow on a kind of liquid circulation loop that is installed between motor car engine and the radiator, relates to a kind of pneumatic type thermostat.

Background technique

Cooling system is the important component part of motor, and thermostat plays crucial effects again in cooling system.What extensively adopt in the engine-cooling system at present is waxtype thermostat, and this thermostat is made up of support, main valve, push rod, paraffin, sebific duct, auxiliary-valve, thermostat shell, spring etc.As temperature sensing medium, utilize the melted paraffin wax volumetric expansion with paraffin, force sebific duct to shrink, thereby promote push rod, valve is opened gradually.Also have ether formula thermostat, it is to charge into ether in folding cylinder, utilizes ether to form vacuum when liquefaction, and the principle of volumetric expansion during vaporization produces folding cylinder and shrinks or elongation, reaches the purpose that control valve opens and closes.

Because the absolute expansion amount of paraffin thermal expansion can not produce enough displacements, promote valve and realize switch motion.Therefore, waxtype thermostat is actually and utilizes hydraulic principle, the push rod of the extruding force promotion minor diameter that expands by the liquid paraffin in the major diameter chamber, and promptly the big piston mode that pushes away small piston increases the push rod stroke, causes the structure relative complex.In addition, also will consider the sealing problem of liquid paraffin, its manufacture difficulty, precision and manufacture cost are higher relatively.Ether formula thermostat expands with variation of temperature constantly because of folding cylinder or shrinks, and causes mechanical fatigue easily, causes folding damage.

Over more than 20 year, carrying out with the research that memory alloy is made thermostat as heat-sensitive element, during this always, someone has delivered research paper, also the someone has applied for patent, but because problems such as its reliability and other combination property never enter the practical stage.

In addition, the somebody studies the electromagnetism thermostat.It is made up of valve, heat responsive element, microprocessor etc.By heat responsive element detection of engine temperature, microprocessor is regulated the aperture of valve by electromagnet, with the temperature of control motor in the scope that is fit to.This thermostat life-span is longer, the control accuracy height.But complex structure, installation, maintenance difficulty, cost height.

Summary of the invention

The purpose of this utility model is to provide that a kind of temperature sensing medium is cheap, simple in structure, stable performance, long pneumatic type thermostat of life-span.

For this reason, the technical solution of the utility model is: a kind of pneumatic type thermostat, form by valve driving mechanism, valve mechanism, carriage; Valve mechanism is made up of valve, valve seat, Returnning spring, spring seat, and valve is contained on the valve seat, and Returnning spring supports by spring seat and is pressed on the valve, and spring seat and valve seat link together, and valve mechanism is contained on the carriage; It is characterized in that: valve driving mechanism be located at valve below, described valve driving mechanism is made up of temperature sensor, inflatable membrane, the spacing back-up ring of piston stroke, piston, piston rod, cylinder barrel; Piston cooperates with the inner chamber of cylinder barrel, and piston rod is connected with piston, and the head of piston rod passes the cylinder barrel upper end and directly withstands on the valve, and the spacing back-up ring of piston stroke is located at the lower end of cylinder barrel, all is provided with vent on the upper end of cylinder barrel, the piston; The temperature-sensitive barrel cavity is equipped with the liquid of boiling point between 50 ℃～70 ℃, and inflatable membrane places the opening of temperature-sensitive bucket, inflatable membrane periphery and the hermetic seal of temperature-sensitive bucket; Described temperature-sensitive bucket places the lower end of cylinder barrel, and links into an integrated entity with cylinder barrel, and then is connected on the carriage.

Working procedure: at normal temperatures or when the temperature of motor is lower than 85 ℃, vaporization phenomenon does not take place in the liquid in the temperature-sensitive bucket under the precompression effect of return spring.Valve is pressed on the valve seat under the precompression effect of return spring, and valve is in closed condition, and the cooling liquid in the motor can only be done the short circle motion, helps the intensification of motor.Along with the temperature of the cooling liquid in the engine water jacket constantly raises, when coolant temperature is higher than uniform temperature (about 85 ℃), reach liquid in the temperature-sensitive bucket under the precompression effect during boiling temperature, liquid in the temperature-sensitive bucket begins vaporization, the pressure of inflatable membrane below is raise, the promotion inflatable membrane moves upward, thereby promotion piston and piston rod move upward.Simultaneously, the impacting force that piston rod promotion valve overcomes return spring moves upward together, with valve open.Greatly about about 90 ℃, after valve is opened fully, piston motion is to the top of cylinder barrel, when the temperature of the liquid in the temperature-sensitive bucket continues to raise, the pressure of inflatable membrane below will increase, and the boiling point of the liquid in the temperature-sensitive bucket increases thereupon, thereby make temperature and its boiling point of the liquid in the temperature-sensitive bucket form a kind of state of equilibrium, liquid in the temperature-sensitive bucket stops vaporization, and thermostat is in a kind of more stable state of equilibrium.When the intensity of cooling of radiator increased, the temperature of the cooling liquid in the engine water jacket decreased, and when water temperature is lower than uniform temperature (about 85 ℃), the liquid in the temperature-sensitive bucket will liquefy, and the pressure of inflatable membrane below reduces.Under the effect of return spring, valve, piston rod, piston move downward together, reduce the aperture of valve, thereby reduce the intensity of cooling of radiator, until throttle down, impel the temperature recovery of motor, keep the normal working temperature that motor is in greater efficiency.

Beneficial effect: this thermostat is mounted in the device of the adjusting engine operating temperature on the motor, it has been broken traditional thermostat and has utilized solid-state liquefaction expansion (paraffin thermostat) generation driving force and utilize vacuum to shrink, elastic force elongation (ether thermostat) drives the intention of valve open, adopt cheap, the organic liquor that boiling point is suitable (normal temperature is down for liquid), utilize the relation of fluid pressure and boiling point, make liquid produce driving force at suitable temperature (optimal temperature of engine operation) vaporized expanding, and the purpose that adopts simple piston cylinder operator transmission of drive force to reach valve opening or close.A kind of so innovative design not only can be regulated the temperature of motor as traditional thermostat, and has simple in structure, low cost and plurality of advantages such as reliability preferably.For automobile thermostat market has increased a kind of not only practical but also can bring the novel product of good economic benefit.

Description of drawings

Fig. 1 is the plan view of piston pneumatic type thermostat structural representation.

Fig. 2 is the inflatable membrane structural front view.

Fig. 3 is an inflatable membrane structure plan view.

Among Fig. 1, the 1st, inflatable membrane, the 2nd, liquid, the 3rd, temperature-sensitive bucket, the 4th, stroke limit back-up ring, the 5th, piston, the 6th, piston rod, the 7th, cylinder barrel, the 8th, return spring, the 9th, spring seat, the 10th, valve, the 11st, valve seat, the 12nd, carriage.

Embodiment

As shown in Figure 1, a kind of pneumatic type thermostat is made up of valve driving mechanism, valve mechanism, carriage.The main component part of valve driving mechanism has liquid 2, temperature-sensitive bucket 3, stroke limit back-up ring 4, piston 5, piston rod 6, the cylinder barrel 7 in inflatable membrane 1, the temperature-sensitive bucket.Cylinder barrel 7 upper edge inwalls play the guiding role to piston 5, piston rod 6; All have the vent that along the circumferential direction distributes on piston 5 and the cylinder barrel 7, advance smoothly and stably so that piston 5 overcomes the resistance of the cooling liquid of vacuum or infiltration.Stroke limit back-up ring 4 guarantees the circumferencial direction sealing with inflatable membrane 1 when detaining the limit.Inflatable membrane 1 is located at the opening of temperature-sensitive bucket 3, provides motivational drive inflatable membrane 1 by 2 vaporized expandings of the liquid in the temperature-sensitive bucket, make inflatable membrane 1 upwards heave and act on piston lower surface, thereby promotion piston 5 and piston rod 6 moves upward.

Liquid 2 in the temperature-sensitive bucket is the liquid of boiling point between 50 ℃～70 ℃, makes that thermostatic valve is can open between 85 ℃～90 ℃ the time at engine water temperature.

Valve mechanism is made up of valve 10, return spring 8 and spring seat 9.Return spring 8 places between spring seat 9 and the valve 10 with certain precompressed amount, and the lower end is pressed on the valve 10, and the upper end acts on spring seat 9.Spring seat 9 lower ends are connected with acquisition with valve seat 11 riveted joints.Valve 10 lower edges are supported on the piston rod shoulder, during liquid 2 vaporized expandings in the temperature-sensitive bucket by piston rod shoulder transferring power with valve open.Valve presses on valve seat when original state, and this also is the state of valve when closing fully.

11 riveted joints of carriage 12 upper ends and valve seat, lower end and temperature sensor 3 link together, and are supporting whole valve driving mechanism.

Can select for use acetone as the liquid in the temperature-sensitive bucket, because its boiling point is 56.48 ℃.Relation according to its boiling point and surface pressure designs return spring, can satisfy design and practical requirement.

Shown in Fig. 2,3 inflatable membrane, the surface 3 of inflatable membrane is the curved surface of broken line shape, this is in order to reduce the amount of deformation of inflatable membrane when expanding, to reduce the tensile stress that inflatable membrane work is, allaying tiredness destroys, and improves working life.

Claims

1, a kind of pneumatic type thermostat is made up of valve driving mechanism, valve mechanism, carriage; Valve mechanism is made up of valve, valve seat, Returnning spring, spring seat, and valve is contained on the valve seat, and Returnning spring supports by spring seat and is pressed on the valve, and spring seat and valve seat link together, and valve mechanism is contained on the carriage; It is characterized in that: valve driving mechanism be located at valve below, described valve driving mechanism is made up of temperature-sensitive bucket, inflatable membrane, the spacing back-up ring of piston stroke, piston, piston rod, cylinder barrel; Piston cooperates with the inner chamber of cylinder barrel, and piston rod is connected with piston, and the head of piston rod passes the cylinder barrel upper end and directly withstands on the valve, and the spacing back-up ring of piston stroke is located at the lower end of cylinder barrel, all is provided with vent on the upper end of cylinder barrel, the piston; The temperature-sensitive barrel cavity is equipped with the liquid of boiling point between 50 ℃～70 ℃, and inflatable membrane places the opening of temperature sensor bucket, inflatable membrane periphery and the hermetic seal of temperature-sensitive bucket; Described temperature-sensitive bucket places the lower end of cylinder barrel, and links into an integrated entity with cylinder barrel, and then is connected on the carriage.

2, a kind of pneumatic type thermostat according to claim 1 is characterized in that: the surface of described inflatable membrane is a broken line shape curved surface.