CN114673648A - Compressor silencer and manufacturing process thereof - Google Patents

Abstract

A compressor muffler and its preparation method, in the field of compressor assembly technology, the preparation method of the compressor muffler, including raw materials drying treatment; heating the baking raw materials in sections; performing high-pressure injection and low-pressure maintaining during injection molding of the silencer component; after injection molding, cooling, demolding, assembling and welding forming are carried out; quality inspection; the invention has the advantages that the preparation process of the silencer is standardized, so that the preparation period and the preparation cost of a finished product can be reduced by simple steps, the quality of the finished product is improved, and the performance index of the silencer can be improved; meanwhile, the structure of the existing silencer is changed, so that the silencing frequency range can be enlarged, and the silencing and noise reducing effects are improved.

Description

Compressor silencer and manufacturing process thereof

Technical Field

The invention relates to the technical field of compressor assembly, in particular to a compressor silencer and a manufacturing process thereof.

Background

Noise generated by the compressor is a main source of refrigerator noise, and the noise is one of important indexes for measuring the quality of the refrigerator compressor. The noise of the compressor of the refrigerator can be classified into pneumatic noise, mechanical noise and electromagnetic noise, wherein the pneumatic noise has the greatest proportion. The pneumatic noise is mainly generated at the air inlet and outlet ends of the compressor, particularly the suction noise is most prominent, the suction process is discontinuous due to the existence of the valve plate, high-pressure expansion exists, and in the pneumatic noise, airflow pulsation becomes an important noise source and is usually controlled by a suction muffler. It follows that the acoustic performance of the suction muffler has a significant impact on the quality of the refrigerator compressor.

In the process of processing and producing the existing suction muffler, as the technological process has no certain technological standard in the preparation process, the existing technological steps are complex, the preparation efficiency is low, the cost is high, and the quality of the prepared finished product is uneven, which is mainly reflected in that the wall thickness of the finished product is uneven, the heat insulation and sound insulation effects are poor, and the technological requirements of the existing muffler cannot be met.

In addition, the structure of the existing suction muffler also has certain defects, for example, the existing suction muffler needs to be designed into a through-hollow structure for installation, that is, the muffler has a left acoustic muffling cavity and a right acoustic muffling cavity, the left side is a first expansion chamber a, the right side is a second expansion chamber B, and the joint between the first expansion chamber a and the second expansion chamber B is a necking installation structure, namely, a through-hollow structure C. Due to the existence of the 'penetration', the length of the expansion chamber is reduced, and the noise elimination frequency range is reduced. Because the total pressure difference is increased, the total pressure loss is large, the influence on the refrigerating capacity of the compressor is large, and the energy efficiency of the compressor is low; moreover, because the muffling chamber is too small, the structural defects cause poor low-frequency muffling capability, and low-frequency sound in a specific frequency band cannot be muffled at all, and the "through" muffling chamber reduces the muffling frequency and the muffling range, which may cause complaints of users due to poor sound quality caused by over-tolerance of a certain frequency band, especially over-tolerance of low-frequency noise.

Disclosure of Invention

In order to solve the technical problems, the invention provides a compressor silencer and a manufacturing process thereof, which can reduce the preparation period and the preparation cost of finished products by simple steps by standardizing the preparation process of the silencer, improve the quality of the finished products and improve the performance index of the silencer; meanwhile, the structure of the existing silencer is changed, so that the silencing frequency range can be enlarged, and the silencing and noise reducing effects are improved.

In order to achieve the purpose, the technical scheme adopted by the invention for solving the technical problems is as follows: the manufacturing process of the compressor silencer comprises the following steps:

step 1: baking the injection molding solid raw material and then putting the baked injection molding solid raw material into a charging barrel of an injection molding machine;

step 2: feeding the baked raw materials into an injection molding machine barrel from a charging barrel for segmented heating, and heating the raw materials to a molten state;

and step 3: when injection molding is started, the pressure applied to the molten material by the top of a screw of the injection molding machine is 80-100 MPa, the injection flow is 36-40 g/s, and when the mass of the molten material in the injection molding machine reaches 10-20% of the initial position, pressure maintaining is carried out, wherein the pressure maintaining is 42-50 MPa, the injection flow is 8-16 g/s, and the pressure maintaining time is 10-20 s;

and 4, step 4: performing injection molding on the silencer component according to the methods in the step 1 and the step 2, and then performing cooling, demolding, assembling and welding forming;

and 5: carrying out quality inspection on the silencer forming part;

step 6: and (7) packaging and warehousing.

The injection molding solid raw material is a PBT (polybutylene terephthalate) granule, the baking temperature of the PBT granule is 130-140 ℃, and the baking time is 4-5 h.

The injection molding machine barrel in the step 2 is sequentially provided with a heating section I, a heating section II, a heating section III, a heating section IV and a heating section V along the injection molding direction, the temperature of the heating section I is 240-260 ℃, the temperature of the heating section II is 260-280 ℃, the temperature of the heating section III is 280-300 ℃, the temperature of the heating section IV is 295-315 ℃, the heating section V is located at a nozzle of the injection molding machine barrel, the temperature of the heating section V is 295-315 ℃, the heating proportion is 50-70%, and the heating time is 10-20 s.

The wall thickness uniformity of the silencer component obtained by injection molding according to the methods in the step 1 and the step 2 is 90-100%, and the molding shrinkage rate is 1-2.3%.

And welding the silencer component by adopting a high-frequency welding machine, wherein the temperature of the high-frequency welding is 250-270 ℃, and the welding time is 4-7 s.

The quality inspection of the silencer formed part in the step 4 comprises tensile strength inspection and pipeline smoothness inspection, wherein the tensile strength inspection method is that after the tensile force of 180-210N is maintained for 4s, if no crack defect occurs at the welding seam, the welding strength is qualified, and if not, the welding strength is unqualified; the method for testing the smoothness of the pipeline comprises the steps that gas with the pressure of 0.35MPa is introduced into an air suction port of a silencer, if the pressure of the gas detected at an air outlet is 0.28-0.35 MPa, the pipeline is smooth, and if the pressure of the gas detected at the air outlet is less than 0.28MPa, the pipeline is blocked and is unqualified.

A compressor silencer adopts the manufacturing process and comprises an upper silencing chamber, a communicating device I, a lower silencing chamber and a communicating device II, wherein the upper silencing chamber is connected with the communicating device I to form a resonant cavity, the lower silencing chamber is connected with the communicating device II and then is welded with the upper silencing chamber to form a first silencing cavity and a second silencing cavity which are communicated with the resonant cavity, and the volume of the second silencing cavity close to the resonant cavity is smaller than that of the first silencing cavity.

The communicating device I comprises a partition plate I in interference fit with the upper silencing chamber, an insertion pipe I integrally formed with the partition plate I is arranged on the partition plate I, and the insertion pipe I is used for communicating the second silencing cavity with the resonant cavity.

The communicator II comprises a partition plate II in interference fit with the lower muffling chamber, an insert pipe II and a wavelength pipe are integrally formed on the partition plate II, the insert pipe II is used for communicating the first muffling cavity with the second muffling cavity, the end part of the wavelength pipe, which is located at one end of the first muffling cavity, is sealed, the length L of the wavelength pipe is lambda/4, and lambda is the wavelength of a muffling frequency band; the separation ratio of the second silencing cavity to the first silencing cavity is 0.3-0.5.

The lower silencing chamber is provided with an air suction port communicated with the first silencing cavity, and the upper silencing chamber is provided with an air outlet communicated with the second silencing cavity;

the port of the upper silencing chamber is in clamping fit with the port of the lower silencing chamber and is connected with the port of the lower silencing chamber in a sealing and welding mode through a welding wire ring;

an oil leakage hole I is formed in the communicating device II, an oil leakage hole II opposite to the oil leakage hole I is formed in the bottom of the lower silencing chamber, and an oil baffle plate is arranged on the lower silencing chamber at the bottom of the oil leakage hole II;

the inner walls of the upper silencing chamber and the lower silencing chamber are in uniform transition and equal in wall thickness.

The invention has the beneficial effects that:

1. the solid raw materials enter the injection molding machine barrel from the charging barrel to be heated in a segmented mode, the raw materials can be heated into a molten state, the injection flowability is improved, when the silencer component is subjected to injection molding, the injection molding process is divided into two stages according to the quantity of the molten materials in the injection molding machine, the two stages comprise a high-pressure injection molding stage and a pressure maintaining stage, the molten materials have a certain die punching speed in the high-pressure injection molding stage, the molten materials can be compacted, and due to the fact that the injection pressure is large and the thermal shrinkage rate is increased, pressure maintaining is carried out when the mass of the molten materials in the injection molding machine reaches 10-20% of the initial position, the compactness and the wall thickness uniformity of a finished product can be increased, the molding shrinkage rate of the finished product is reduced, and the heat insulation and sound insulation effects are good.

2. According to the invention, the existing silencer structure is improved, the cavity structure formed by the upper silencing chamber and the lower silencing chamber is divided into the first silencing cavity, the second silencing cavity and the resonant cavity which are communicated through the communicating device I and the communicating device II, and after airflow enters the first silencing cavity from the air suction port, the first silencing cavity has a better silencing effect in a high-frequency section due to the longer length and larger volume of the first silencing cavity; the airflow enters the second silencing cavity with a longer length through the insertion tube II on the communicator II, and the peak value of the specific medium-high frequency narrow-band noise can be weakened due to the fact that the communicator II is further provided with the wavelength tube with the length of lambda/4 and one end of the wavelength tube is closed; the air current gets into the resonant cavity through the insert tube I on the UNICOM ware I again, through the position of adjusting the length of insert tube I, internal diameter and UNICOM ware I, can eliminate the noise of specific lower frequency channel, has increased the frequency range of eliminating the noise, can obtain the transmission loss of more frequency channels, makes the noise elimination noise reduction effect better.

3. The partition plate I is in interference fit with the upper silencing chamber, and the partition plate II is in interference fit with the lower silencing chamber, so that the impact of pulsating airflow on the communicating device I and the communicating device II is avoided to generate regenerative noise, the surrounding interference fit also prevents sound waves from passing through the matching part of the communicating device II, the silencing effect is good, meanwhile, welding wires are connected with the upper silencing chamber and the lower silencing chamber in a high-frequency welding mode to be tightly connected together, the integral tensile strength is improved, and the reliability is better.

4. The first silencing cavity and the second silencing cavity designed by the invention have the advantages of longer length, wider width, larger integral volume, uniform transition of inner walls and equal wall thickness, airflow enters the first silencing cavity from the air suction port in a jet flow mode and is mixed with gas with lower flow velocity in the cavity, although a certain range of vortex and backflow are formed in the cavity, the velocity distribution in the first silencing cavity is not uniform, but energy dissipation and loss are caused due to the larger volume of the first silencing cavity, the pressure reduction amount of a refrigerant in the flowing process is reduced, the local resistance loss is small, the total pressure loss is small due to the reduction of the total pressure difference, meanwhile, the integral volume of the silencing cavity is larger, more refrigerants can be collected, the specific volume of air suction is reduced, and the refrigerating capacity of a compressor is improved.

Drawings

The contents of the various figures of the present specification and the labels in the figures are briefly described as follows:

FIG. 1 is a schematic view of a prior art suction muffler;

FIG. 2 is a process flow diagram of muffler processing of the present invention;

FIG. 3 is a schematic view of the muffler of the present invention;

FIG. 4 is a full sectional view of FIG. 3;

FIG. 5 is an exploded view of FIG. 3;

FIG. 6 is a simulation diagram showing the relationship between frequency and transmission loss obtained after modeling of the mufflers in examples 1 and 2 of the present invention and comparative examples 1 and 3;

FIG. 7 is a simulation diagram showing the relationship between frequency and transmission loss obtained after modeling of mufflers in examples 2 and 3 of the present invention and comparative examples 2 and 3;

the labels in the above figures are: 1. the welding wire ring silencing device comprises an upper silencing chamber, an air outlet 11, a communicating device I2, a partition plate I21, a partition plate I22, an insertion pipe I3, a lower silencing chamber 31, an air suction port 32, an oil leakage hole II 33, an oil baffle plate 4, a communicating device II 41, a partition plate II 42, an insertion pipe II 43, a wave pipe 44, an oil leakage hole I5, a resonant cavity 6, a first silencing cavity 7, a second silencing cavity 8, a welding wire ring A, a first expansion chamber B, a second expansion chamber C and a penetrating structure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and the following embodiments are used for illustrating the present invention and are not intended to limit the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The specific implementation scheme of the invention is as follows: as shown in fig. 2, a manufacturing process of a compressor muffler includes the following steps:

step 1: baking an injection molding solid raw material and putting the injection molding solid raw material into a charging barrel of an injection molding machine, wherein the injection molding solid raw material is a PBT (polybutylene terephthalate) granule, the baking temperature of the PBT granule is 130-140 ℃, and the baking time is 4-5 h, so that the PBT granule is fully baked and softened;

step 2: the roasted raw material enters an injection molding machine barrel from a charging barrel to be heated in a segmented mode so as to be heated to a molten state: the injection molding machine barrel is sequentially provided with a heating section I, a heating section II, a heating section III, a heating section IV and a heating section V along the injection molding direction, the temperature of the heating section I is 240-260 ℃, the temperature of the heating section II is 260-280 ℃, the temperature of the heating section III is 280-300 ℃, the temperature of the heating section IV is 295-315 ℃, the heating section V is located at a nozzle of the injection molding machine barrel, the temperature of the heating section V is 295-315 ℃, the heating proportion is 50-70%, the actual heating temperature at the nozzle is the product of the temperature of the heating section V and the heating proportion, when the heating proportion reaches the set proportion, the injection molding machine barrel is suspended and enters a heat preservation state, and the heat preservation heating time is 10-20 s. The raw materials are subjected to gradient heating, so that the roasted raw materials are heated from low temperature to high temperature, the PBT granules can be heated to a fully molten state, and the fluidity of injection is improved.

And step 3: when injection molding is started, the pressure applied to the molten material by the top of a screw of an injection molding machine is 80-100 MPa, the injection flow is 36-40 g/s, no material exists in a forming mold in an initial injection molding state, when the injection pressure is increased, the material flow resistance of PBT plastic can be overcome, so that the molten material has a certain stamping speed, the shearing action of the material on a mold gate is large, the orientation degree is high, the thermal shrinkage rate of the material is increased along with the increase of the injection pressure, in order to avoid the influence of the initial injection pressure on the molding shrinkage rate, pressure maintaining is carried out when the mass of the molten material in the injection molding machine reaches 10-20% of the initial position, the pressure maintaining pressure is 42-50 MPa, the injection flow is 8-16 g/s, the pressure maintaining time is 10-20 s, the pressure maintaining is the injection pressure when a certain material exists in a mold cavity, and the shearing action of the material at the gate is smaller than the initial injection pressure, increasing the dwell pressure at this moment can make the closely knit degree of injection molding increase, and the thermal shrinkage reduces, and elastic recovery increases simultaneously to make the shaping shrinkage factor reduce. The size change of the injection sample piece parallel to the material flow direction is tested by adopting a magnetic gauge stand dial indicator according to a formula

In the formula, M is the size of a die cavity of the die at room temperature, L is the size of a sample of the corresponding die cavity, and the molding shrinkage rate is 1-2.3% after testing. Therefore, the wall thickness of the silencer component can be guaranteed to be uniform by adopting high-pressure injection molding and pressure maintaining, the wall surface of a silencing chamber can be extracted during testing, the oil pointer caliper is adopted to directly measure the wall surface of the silencing chamber aiming at a straight surface, the point changing position is changed for testing, the arc surface and the arc area are intercepted, the sharp point thousandths are respectively used for measuring different positions for measuring and measuring, the wall thickness uniformity of the silencer component measured by the method is 90-100%, and the heat insulation and sound insulation effects are good.

And 4, step 4: and (3) performing injection molding on the silencer component according to the method in the step (1) and the step (2), cooling, demolding, assembling and welding for forming, welding the silencer component by adopting a high-frequency welding machine during welding, wherein the temperature of high-frequency welding is 250-270 ℃, and the welding time is 4-7 s.

And 5: performing quality inspection on the silencer formed part, including tensile strength inspection and pipeline smoothness inspection, wherein the tensile strength inspection method is that after the tensile force of 180-210N is adopted and maintained for 4s, if no crack defect appears at a welding seam, the welding strength is qualified, and if not, the welding strength is unqualified; the method for detecting the smoothness of the pipeline comprises the steps of introducing gas with the pressure of 0.35MPa into a gas suction port 31 of a silencer, detecting that the gas pressure is 0.28-0.35 MPa at a gas outlet 11, ensuring that the pipeline is smooth, and detecting that the gas pressure is less than 0.28MPa at the gas outlet 11, and blocking the pipeline and being unqualified.

Step 6: and (7) packaging and warehousing.

As shown in fig. 3 to 5, the compressor muffler manufactured by the above manufacturing process has the following specific structure: the compressor silencer comprises an upper silencing chamber 1, a communicating device I2, a lower silencing chamber 3 and a communicating device II 4, wherein the upper silencing chamber 1 is connected with the communicating device I2 to form a resonant cavity 5, the lower silencing chamber 3 is connected with the communicating device II 4 and then is welded with the upper silencing chamber 1 to form a first silencing cavity 6 and a second silencing cavity 7 which are communicated with the resonant cavity 5, the volume of the second silencing cavity 7 close to the resonant cavity 5 is smaller than that of the first silencing cavity 6, after air flow enters the first silencing cavity 6, the first silencing cavity 6 has longer length and larger volume, so that the silencing effect of the first silencing cavity 6 in a high frequency band is better, the air flow enters the second silencing cavity 7 from the first silencing cavity 6 to eliminate sound in a middle high frequency band, the second silencing cavity 7 enters the resonant cavity 5 to eliminate sound in a specific noise in a lower frequency band, the silencing frequency range is increased, and the transmission loss in more frequency bands can be obtained, the silencing and noise reducing effects are better.

The length of the first muffling cavity 6 and the length of the second muffling cavity 7 are longer, the width is wider, the whole volume is larger, the inner walls of the first muffling cavity 6 and the second muffling cavity 7 are in uniform transition, the wall thickness is equal, airflow enters the first muffling cavity 6 in a jet flow mode through the air suction port 31 and is mixed with gas with lower flow velocity in the cavity, although vortices and backflow in a certain range are formed in the cavity, the velocity distribution in the first muffling cavity 6 is not uniform, but energy dissipation and loss are caused due to the larger volume of the first muffling cavity 6, the pressure reduction amount of the refrigerant in the flowing process is reduced, the local resistance loss is small, the total pressure loss is smaller due to the reduction of the total pressure difference, meanwhile, the whole volume of the muffling cavity is larger, more refrigerants can be collected, the specific volume suction is reduced, and the refrigerating capacity of the compressor is improved.

Specifically, UNICOM ware I2 wherein includes with 1 interference fit's of upper silencing room baffle I21, baffle I21 is all around than the unilateral big 0.15 ~ 0.35mm of the fitting surface of upper silencing room 1, be provided with on the baffle I21 with one body forming's insert tube I22, insert tube I22 communicates second silencing cavity 7 and resonant cavity 5 mutually and links, insert tube I22's one end stretches into in the second silencing cavity 7, the other end stretches into in the resonant cavity 5.

The refrigerant is gas, the mass m of the refrigerant in the insertion pipe I22 and the volume V of the resonant cavity 5 form a mass spring system, and the formula of the noise elimination frequency of the mass spring system is as follows:

wherein f is₀The noise elimination frequency of the resonant cavity 5 is shown, c is sound velocity, S is the opening area of the insertion tube I22, V is the volume of the resonant cavity 5, t is the length of the insertion tube I22, and d is the correction quantity of the open end of the insertion tube I22; from this, the muffling frequency f of the resonant cavity 5 is known₀The opening area S of the insertion tube I22, the volume V of the resonance chamber 5, and the length t of the insertion tube I22.

The muffling frequency f of the resonant cavity 5₀Mainly for specific frequency band low frequency sound, when needing to further reduce the noise elimination to lower frequency, can move baffle I21 downwards, and then the volume V of resonant cavity 5 becomes big, or reduces the bore of inserting pipe I22, and the open area S that inserts pipe I22 diminishes, or lengthens the length t of inserting pipe I22, all can make resonant cavity 5 carry out the noise elimination to lower frequency sound. Can be silenced according to the formula of the silencing frequency and the size of the frequency to be silenced

By changing the opening area S of the insertion tube I22, the volume V of the resonance chamber 5, the insertion tube IThe length t of 22 achieves sound attenuation at a particular frequency.

Specifically, the communicator II 4 comprises a partition plate II 41 in interference fit with the lower muffling chamber 3, the periphery of the partition plate II 41 is 0.15-0.35 mm larger than the unilateral size of the fitting surface of the lower muffling chamber 3, an insertion pipe II 42 and a wavelength pipe 43 which are integrally formed are arranged on the partition plate II 41, the insertion pipe II 42 is used for communicating the first muffling chamber 6 with the second muffling chamber 7, the wavelength pipe 43 is located at one end of the first muffling chamber 6 and is sealed, the insertion pipe is an 1/4 wavelength pipe, the 1/4 wavelength pipe is a passive muffler, when sound waves enter the wavelength pipe 43 from the second muffling chamber 7, the sound waves are reflected back to the second muffling chamber 7 by the closed end of the wavelength pipe 43, and sound waves of certain frequencies and sound waves of the same frequency in the second muffling chamber 7 are mutually offset due to opposite phases, so that the purpose of eliminating the sound waves of specific frequency is achieved. The noise elimination effect of the wavelength tube 43 is evaluated by using the transmission loss, and the formula of the transmission loss of the wavelength tube 43 is

L is the length of the wavelength tube 43, m is the ratio of the cross-sectional area of the wavelength tube 43 to the cross-sectional area of the second muffling chamber 7, and λ is the acoustic wavelength. When in use

(n is a natural number), the transmission loss of the wavelength tube 43 is the largest. At this time, the process of the present invention,

resonant frequency of the waveguide 43

The higher the sound attenuation frequency L of the wavelength tube 43, the shorter L, and the lower the sound attenuation frequency L of the wavelength tube 43. The length of the wave tube 43 is determined according to the muffled frequency band,

l is the length of the wavelength tube 43 and n is the order of the acoustic waveAnd λ is the wavelength of the sound wave, and when n is 1,

i.e. the length of the wave length tube 43 being the wavelength of the sound wave

The peak value of the noise in a specific middle-high frequency narrow frequency band can be weakened.

According to the invention, the partition plate I21 is in interference fit with the upper silencing chamber 1, and the partition plate II 41 is in interference fit with the lower silencing chamber 3, so that the regenerated noise generated by the impact of pulsating airflow on the communicator I2 and the communicator II 4 is avoided, and the sound waves are prevented from passing through the matching part of the communicator II 4 due to the interference fit at the periphery, so that the silencing effect is good.

Specifically, the second muffling cavity 7 and the first muffling cavity 6 are equal in length and width, the separation ratio of the second muffling cavity 7 to the first muffling cavity 6 is 0.3-0.5, that is, the separation ratio H1/H of the second muffling cavity 7 to the first muffling cavity 6 is 0.3-0.5, preferably 0.4, since the wavelength of the high-frequency noise is short, reflection and interference are easy to occur on a discontinuous structure interface, so that the purpose of noise reduction is achieved, and when the height of the second muffling cavity 7 is smaller than the height of the first muffling cavity 6, the high-frequency noise with a short wavelength is sufficiently muffled in the first muffling cavity 6; the medium-high frequency noise with longer wavelength enters the second silencing cavity 7, after the sound wave enters the wave length pipe 43 from the second silencing cavity 7, the sound wave is reflected back to the second silencing cavity 7 by the closed end of the wave length pipe 43, the sound wave with specific frequency and the sound wave with the same frequency in the second silencing cavity 7 are mutually offset due to opposite phases, and the sound elimination of the medium-high frequency noise sound wave with specific frequency is realized; the low-frequency noise sound wave with longer wavelength enters the resonant cavity 5 to eliminate noise of a specific lower frequency band, so that the frequency range of noise elimination is increased, transmission loss of more frequency bands can be obtained, and the noise elimination and reduction effects are better.

In addition, an air suction port 31 communicated with the first muffling chamber 6 is arranged on the lower muffling chamber 3, an air outlet 11 communicated with the second muffling chamber 7 is arranged on the upper muffling chamber 1, a port of the upper muffling chamber 1 is in clamping fit with a port of the lower muffling chamber 3, namely, an annular groove is arranged on the port of the upper muffling chamber 1 in the circumferential direction, a boss clamped with the annular groove is arranged on the port of the lower muffling chamber 3 in the circumferential direction, and a welding wire ring 8 is arranged on the port of the upper muffling chamber 1, so that the muffling chamber and the lower muffling chamber 3 are connected in sealing welding after being clamped, and the structural strength of the whole muffler is improved.

Wherein the communicating device II 4 is provided with an oil leakage hole I44, the bottom of the lower muffling chamber 3 is provided with an oil leakage hole II 32 opposite to the oil leakage hole I44, the lower muffling chamber 3 at the bottom of the oil leakage hole II 32 is provided with an oil baffle plate 33, because the refrigerant and the refrigerating machine oil are completely mutually soluble, when the refrigerant is sucked into each silencing cavity, the oil is also brought into each silencing cavity, because the density of the oil is larger, when more and more refrigerants pass through the silencing cavity, more oil is brought in to form oil drops with larger mass, finally the oil drops fall to the bottom of the lower silencing chamber 3 through the oil leakage hole I44, the oil drops are outwards discharged from the oil leakage hole II 32 on the lower silencing chamber 3 and are outwards guided by the oil baffle plate 33, and the refrigerant oil can not be sucked into the lower silencing chamber 3 again through the oil leakage hole II 32, so that the refrigerant oil is prevented from entering a compressor system through the air outlet 11 of the upper silencing chamber 1, and the defects that a valve plate is damaged due to wet compression in the compression process, and the compressor is blocked and generates noise due to impurities are avoided.

Example 1

As shown in fig. 3 to 5, in the compressor muffler having the above-described configuration, the separation ratio of the second muffling chamber 7 to the first muffling chamber 6 is 0.3, the first muffling chamber 6 has a length of 63mm, a width of 25mm and a height of 45mm, the second muffling chamber 7 has a length of 63mm, a width of 25mm and a height of 13.5mm, the wave length pipe has a length of 20mm, and the opening area S of the insertion pipe i 22 is 12.56mm²The volume V of the resonant cavity 5 is 1920mm³The length t of the insertion tube I22 was 6 mm.

Example 2

The difference from embodiment 1 is that the separation ratio of the second muffling chamber 7 to the first muffling chamber 6 is 0.4, the height of the first muffling chamber 6 is 42mm, and the height of the second muffling chamber 7 is 16.8 mm.

Example 3

The difference from embodiment 1 is that the separation ratio of the second muffling chamber 7 to the first muffling chamber 6 is 0.5, the height of the first muffling chamber 6 is 40mm, and the height of the second muffling chamber 7 is 20 mm.

Comparative example 1

The difference from embodiment 1 is that the separation ratio of the second muffling chamber 7 to the first muffling chamber 6 is 0.25, the height of the first muffling chamber 6 is 48mm, and the height of the second muffling chamber 7 is 12 mm.

Comparative example 2

The difference from embodiment 1 is that the separation ratio of the second muffling chamber 7 to the first muffling chamber 6 is 0.55, the height of the first muffling chamber 6 is 38mm, and the height of the second muffling chamber 7 is 20.9 mm.

Comparative example 3

As shown in FIG. 1, in the muffler of the related art, the volume of the first expansion chamber is 8726mm³The volume of the second expansion chamber is 10423mm³The "through-air" bottom between the first expansion chamber and the second expansion chamber has a width of 27mm and a height of 30 mm.

As shown in fig. 6 and 7, the abscissa is frequency f/Hz, and the ordinate is transmission loss TL/dB, and the mufflers in the above examples 1 to 3 and comparative examples 1 to 3 are modeled in LMS virtual. lab software, respectively, to obtain simulation graphs of the relationship between frequency and transmission loss, and it can be seen from the graphs that the muffling effect of the present invention is better than that of comparative example 3 in the low frequency band, particularly, the transmission loss is significantly higher than that of the muffler in the background art at 700Hz, and the transmission loss of the present invention is also higher than that of the muffler in the background art at medium and high frequencies such as 1000 to 2000Hz, 2300 to 2800Hz, and 3600 Hz. The invention increases the volume of each silencing cavity, and sets the separation ratio of the second silencing cavity 7 and the first silencing cavity 6, and adds the wavelength tube 43, the resonant cavity 5 and the like.

Comparing the simulation diagrams of examples 1 to 3 and comparative examples 1 and 2, it can be seen that when the separation ratio of the second muffling chamber 7 to the first muffling chamber 6 is 0.4, the muffling effect of the high-frequency band 1000 to 2000Hz, 2300 to 2800Hz is the best, and the noises of the two high-frequency bands are the most common in mufflers, and when the separation ratio of the second muffling chamber 7 to the first muffling chamber 6 is 0.25 and 0.55, the transmission loss of the high-frequency band 1000 to 2000Hz is equivalent to the transmission loss of the separation ratios of 0.3, 0.4 and 0.5, and the transmission loss of the high-frequency band 2300 to 2800Hz is significantly lower than the transmission loss of the separation ratios of 0.3, 0.4 and 0.5, so that when the separation ratio of the second muffling chamber 7 to the first muffling chamber 6 is 0.3 to 0.5, the muffling effect of the high-frequency band is better, and particularly the best when the separation ratio is 0.4.

Example 4

The manufacturing process of the compressor silencer comprises the following steps:

step 1: incoming material inspection: including detecting the type, weight and water content of the raw materials.

Step 2: drying treatment of raw materials: and (3) baking the PBT granules for 4-5 h at the temperature of 130-140 ℃ by using an oven, and fully drying and softening the PBT granules.

And step 3: heating the baking raw materials in a segmented manner: and (2) feeding the baked PBT granules into an injection molding machine barrel through a charging barrel, and sequentially arranging the injection molding machine barrel into a heating section I, a heating section II, a heating section III, a heating section IV and a heating section V along the injection molding direction, so that the PBT granules are subjected to gradient heating along the injection molding direction, wherein the heating temperatures are respectively 250 ℃, 270 ℃, 290 ℃ and 305 ℃, the heating temperature close to a nozzle is 305 ℃, the heating proportion is 68%, and the heating time is 18s, and the PBT granules are heated into a molten state.

And 4, step 4: injection molding of the muffler assembly: sequentially injecting an upper silencing chamber 1, a communicating device I2, a lower silencing chamber 3 and a communicating device II 4, and cooling and demoulding after injection.

The injection molding method of the silencer component comprises the following steps: 1) when injection molding is started, the pressure applied to the molten material by the top of a screw of the injection molding machine is 80MPa, the injection flow is 38g/s, and when the mass (volume) of the molten material in the injection molding machine reaches 15% of the initial position, pressure maintaining is carried out, the pressure maintaining is 42MPa, the injection flow is 12g/s, and the pressure maintaining time is 15 s. 2) After the pressure holding, the mold was removed after cooling for 10 seconds.

And 5: assembling a silencer component: according to the size of the silencing frequency, the communicating device I2 is pressed at a set position in the upper silencing chamber 1, so that the communicating device I2 is in interference fit with the upper silencing chamber 1; and (3) pressing the communicating device II 4 at a set position in the lower muffling chamber 3 to ensure that the communicating device II 4 is in interference fit with the lower muffling chamber 3 and the separation ratio of the formed second muffling cavity 7 to the first muffling cavity 6 is 0.4.

Step 6: welding the silencer component: the welding wire ring 8 is placed in the upper silencing chamber 1, the ports of the upper silencing chamber 1 and the lower silencing chamber 3 are in butt joint connection, then the ports of the upper silencing chamber 1 and the lower silencing chamber 3 are welded through a high-frequency welding machine, the high-frequency welding temperature is 250-270 ℃, and the welding time is 4-7 s.

And 7: quality inspection of the silencer molding part:

and (3) testing the tensile strength: and (3) pulling the upper silencing chamber 1 and the lower silencing chamber 3 by using a tensile strength testing machine with a tensile force of 180-210N, and after maintaining for 4s, finding that no crack defect occurs at the welding seam, wherein the welding strength is qualified.

And (3) checking the smoothness of the pipeline: the gas with the pressure of 0.35MPa is introduced into the air inlet 31 of the silencer, the air pressure detected at the air outlet 11 is 0.3MPa, and the pipeline is smooth.

And 8: and (7) packaging and warehousing.

The performance of the silencer component obtained by the process is detected to obtain: the wall thickness uniformity of the upper silencing chamber 1 is 90-93%, and the molding shrinkage rate is 1.6-2.3%; the wall thickness uniformity of the lower muffling chamber 3 is 91-93%, and the molding shrinkage rate is 1.7-2.1%.

Example 5

The difference from example 4 is that: the injection molding method of the silencer component comprises the following steps: 1) when injection molding is started, the pressure applied to the molten material by the top of a screw of the injection molding machine is 90MPa, the injection flow is 38g/s, and when the mass (volume) of the molten material in the injection molding machine reaches 15% of the initial position, pressure maintaining is carried out, the pressure maintaining is 46MPa, the injection flow is 12g/s, and the pressure maintaining time is 15 s. 2) After the pressure holding, the mold was removed after cooling for 10 seconds.

Further examination of the performance of the muffler assembly obtained by the above process yielded: the wall thickness uniformity of the upper silencing chamber 1 is 95-97%, and the molding shrinkage rate is 1.4-1.5%; the wall thickness uniformity of the lower muffling chamber 3 is 95-98%, and the molding shrinkage rate is 1.3-1.5%.

It can be known from the embodiments 4 and 5 that when the injection pressure is low, it is inconvenient to inject the melt of the charging barrel into the cavity of the mold to make the melt fully contact with the cavity, and because of the existence of a certain injection proportion, after most of the melt is injected into the cavity, the basic molding muffling cavity has certain deviation of wall thickness due to the objective space position and temperature distribution of the mold, and if the holding pressure is low, the wall thickness is inconvenient to fill and compact. Therefore, the wall thickness of the silencer is not uniformly distributed, the sound insulation effect of a thin place is poor, the heat insulation effect is poor, heat exchange is easy to occur with the refrigerant collected by the shell, and the refrigerating capacity is reduced. By increasing the injection pressure, the PBT molten material is convenient to spread the mould, the whole mould surface is filled with the PBT molten material, the PBT molten material flows well on the mould surface under certain pressure maintaining conditions, the PBT molten material is fully melted, the wall thickness of the whole silencer is uniform, the heat insulation, sound insulation and noise reduction effects are good, the injection pressure is increased, the compactness of the PBT product is increased, the heat shrinkage rate is reduced, the elastic recovery is increased, and the molding shrinkage rate is reduced.

Example 6

The difference from example 4 is that: the injection molding method of the silencer component comprises the following steps: 1) when injection molding is started, the pressure applied to the molten material by the top of a screw of an injection molding machine is 90MPa, the injection flow is 40g/s, and when the mass (volume) of the molten material in the injection molding machine reaches 15% of the initial position, pressure maintaining is carried out, the pressure maintaining pressure is 46MPa, the injection flow is 16g/s, and the pressure maintaining time is 2 s. 2) After the pressure maintaining is finished, cooling for 10s and then demoulding;

detecting the performance of the silencer assembly to obtain: the wall thickness uniformity of the upper silencing chamber 1 is 96-98%, and the molding shrinkage rate is 1-1.3%; the wall thickness uniformity of the lower muffling chamber 3 is 97-99%, and the molding shrinkage rate is 1-1.2%.

It can be seen from examples 4 and 6 that the increase of the injection flow rate is convenient for the molten PBT material to spread the mold, and under certain pressure maintaining conditions, the molten PBT material flows well on the surface of the mold and is fully molten, so that the wall thickness of the whole silencer is uniform and consistent, the heat insulation, sound insulation and noise reduction effects are good, and the increase of the injection flow rate is equivalent to the increase of the injection rate, so that the material temperature is reduced slowly, which is beneficial to pressure transmission and pressure maintaining, and the molding shrinkage rate is reduced.

Comparative example 4

The difference from example 5 is that: when the mass (volume) of the molten material in the injection molding machine reaches 5% of the initial position, pressure holding is performed, the pressure holding pressure is 46MPa, the injection flow is 12g/s, and the pressure holding time is 15 s.

Detecting the performance of the silencer assembly to obtain: the wall thickness uniformity of the upper silencing chamber 1 is 76-86%, and the molding shrinkage rate is 2.5-4.8%; the wall thickness uniformity of the lower sound-deadening chamber 3 is 78-84%, and the molding shrinkage rate is 2.8-3.6%.

Comparative example 5

The difference from example 4 is that: when the mass (volume) of the molten material in the injection molding machine reached 30% of the initial position, pressure holding was performed at 46MPa, the injection flow rate was 12g/s, and the pressure holding time was 15 s.

Detecting the performance of the silencer assembly to obtain: the wall thickness uniformity of the upper silencing chamber 1 is 72-83%, and the molding shrinkage rate is 3.2-5.4%; the wall thickness uniformity of the lower sound-deadening chamber 3 is 75-86%, and the molding shrinkage rate is 4.1-6.2%.

Therefore, it can be seen from the examples 5, the comparative examples 4 and the comparative examples 5 that the time for starting the pressure holding has a great influence on the wall thickness uniformity and the molding shrinkage rate of the sound-absorbing chamber, and when the mass (volume) of the molten material in the injection molding machine reaches 10 to 20% of the initial position, the wall thickness uniformity of the obtained finished product is 90 to 100% and the molding shrinkage rate is 1 to 2.3% under certain injection pressure, pressure holding pressure and injection flow rate. And when the ratio of the mass of the molten material in the injection molding machine to the mass of the initial position is less than 10%, because the amount of the molten material in the injection molding machine is relatively small, more molten material is injected into the mold, the amount of the molten material participating in pressure maintaining is relatively small, the molten material cannot be fully rebounded, and the wall thickness uniformity and the molding shrinkage rate of the product are reduced.

In conclusion, the preparation process of the silencer is standardized, so that the preparation period and the preparation cost of a finished product can be reduced by simple steps, the quality of the finished product is improved, and the performance index of the silencer can be improved; meanwhile, the structure of the existing silencer is changed, so that the silencing frequency range can be enlarged, and the silencing and noise-reducing effects are improved.

While the foregoing is directed to the principles of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims (10)

1. The manufacturing process of the compressor silencer is characterized by comprising the following steps:

step 1: baking the injection molding solid raw material and then putting the baked injection molding solid raw material into a charging barrel of an injection molding machine;

step 2: feeding the baked raw materials into an injection molding machine barrel from a charging barrel for segmented heating, and heating the raw materials to a molten state;

and step 3: when injection molding is started, the pressure applied to the molten material by the top of a screw of the injection molding machine is 80-100 MPa, the injection flow is 36-40 g/s, and when the mass of the molten material in the injection molding machine reaches 10-20% of the initial position, pressure maintaining is carried out, wherein the pressure maintaining is 42-50 MPa, the injection flow is 8-16 g/s, and the pressure maintaining time is 10-20 s;

and 4, step 4: performing injection molding on the silencer component according to the methods in the step 1 and the step 2, and then performing cooling, demolding, assembling and welding forming;

and 5: carrying out quality inspection on the silencer forming part;

step 6: and (7) packaging and warehousing.

2. The process for manufacturing a compressor muffler according to claim 1, wherein: the injection molding solid raw material is a PBT (polybutylene terephthalate) granule, the baking temperature of the PBT granule is 130-140 ℃, and the baking time is 4-5 h.

3. The process for manufacturing a compressor muffler according to claim 1, wherein: the injection molding machine barrel in the step 2 is sequentially provided with a heating section I, a heating section II, a heating section III, a heating section IV and a heating section V along the injection molding direction, the temperature of the heating section I is 240-260 ℃, the temperature of the heating section II is 260-280 ℃, the temperature of the heating section III is 280-300 ℃, the temperature of the heating section IV is 295-315 ℃, the heating section V is located at a nozzle of the injection molding machine barrel, the temperature of the heating section V is 295-315 ℃, the heating proportion is 50-70%, and the heating time is 10-20 s.

4. The manufacturing process of compressor muffler according to claim 1, wherein: the wall thickness uniformity of the silencer component obtained by injection molding according to the methods in the step 1 and the step 2 is 90-100%, and the molding shrinkage rate is 1-2.3%.

5. The process for manufacturing a compressor muffler according to claim 1, wherein: and welding the silencer component by adopting a high-frequency welding machine, wherein the temperature of the high-frequency welding is 250-270 ℃, and the welding time is 4-7 s.

6. The process for manufacturing a compressor muffler according to claim 1, wherein: the quality inspection of the silencer formed part in the step 4 comprises tensile strength inspection and pipeline smoothness inspection, wherein the tensile strength inspection method is that after the tensile force of 180-210N is maintained for 4s, if no crack defect occurs at the welding seam, the welding strength is qualified, and if not, the welding strength is unqualified; the method for testing the smoothness of the pipeline comprises the steps that gas with the pressure of 0.35MPa is introduced into an air suction port of a silencer, if the pressure of the gas detected at an air outlet is 0.28-0.35 MPa, the pipeline is smooth, and if the pressure of the gas detected at the air outlet is less than 0.28MPa, the pipeline is blocked and is unqualified.

7. A compressor silencer adopting the manufacturing process of any one of claims 1 to 6, characterized in that: the lower silencing chamber is connected with the communicating device II and then is welded with the upper silencing chamber to form a first silencing cavity and a second silencing cavity which are communicated with the resonance cavity, and the volume of the second silencing cavity close to the resonance cavity is smaller than that of the first silencing cavity.

8. The compressor muffler of claim 7, wherein: the communicating device I comprises a partition plate I in interference fit with the upper silencing chamber, an insert pipe I integrally formed with the partition plate I is arranged on the partition plate I, and the insert pipe I enables the second silencing cavity and the resonant cavity to be communicated.

9. The compressor muffler of claim 7, wherein: the communicator II comprises a partition plate II in interference fit with the lower muffling chamber, an insert pipe II and a wavelength pipe are integrally formed on the partition plate II, the insert pipe II is used for communicating the first muffling cavity with the second muffling cavity, the end part of the wavelength pipe, which is located at one end of the first muffling cavity, is sealed, the length L of the wavelength pipe is lambda/4, and lambda is the wavelength of a muffling frequency band; the separation ratio of the second silencing cavity to the first silencing cavity is 0.3-0.5.

10. The compressor muffler of claim 7, wherein: the lower silencing chamber is provided with an air suction port communicated with the first silencing cavity, and the upper silencing chamber is provided with an air outlet communicated with the second silencing cavity;

the port of the upper silencing chamber is in clamping fit with the port of the lower silencing chamber and is connected with the port of the lower silencing chamber in a sealing and welding mode through a welding wire ring;

an oil leakage hole I is formed in the communicating device II, an oil leakage hole II opposite to the oil leakage hole I is formed in the bottom of the lower silencing chamber, and an oil baffle plate is arranged on the lower silencing chamber at the bottom of the oil leakage hole II;

the inner walls of the upper silencing chamber and the lower silencing chamber are in uniform transition and equal in wall thickness.

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